Wide-bandgap two-dimensional (2D) β-TeO_(2) has been reported as a high-mobility p-type transparent semiconductor [Nat. Electron. 4 277 (2021)], attracting significant attention. This "breakthrough" not onl...Wide-bandgap two-dimensional (2D) β-TeO_(2) has been reported as a high-mobility p-type transparent semiconductor [Nat. Electron. 4 277 (2021)], attracting significant attention. This "breakthrough" not only challenges the conventional characterization of TeO_(2) as an insulator but also conflicts with the anticipated difficulty in hole doping of TeO_(2) by established chemical trends. Notably, the reported Fermi level of 0.9 eV above the valence band maximum actually suggests that the material is an insulator, contradicting the high hole density obtained by Hall effect measurement. Furthermore, the detected residual Se and the possible reduced elemental Te in the 2D β-TeO_(2) samples introduces complexity, considering that elemental Se, Te, and Te_(1−x)Se_(x) themselves are high-mobility p-type semiconductors. Therefore, doubts regarding the true cause of the p-type conductivity observed in the 2D β-TeO_(2) samples arise. In this Letter, we employ density functional theory calculations to illustrate that TeO_(2), whether in its bulk forms of α-, β-, or γ-TeO_(2), or in the 2D β-TeO_(2) nanosheets, inherently exhibits insulating properties and poses challenges in carrier doping due to its shallow conduction band minimum and deep valence band maximum. Our findings shed light on the insulating properties and doping difficulty of TeO_(2), contrasting with the claimed p-type conductivity in the 2D β-TeO_(2) samples, prompting inquiries into the true origin of the p-type conductivity.展开更多
p-type transparent oxide semiconductors(TOSs)are significant in the semiconductor industry,driving advancements in optoelectronic technologies for transparent electronic devices with unique properties.The recent disco...p-type transparent oxide semiconductors(TOSs)are significant in the semiconductor industry,driving advancements in optoelectronic technologies for transparent electronic devices with unique properties.The recent discovery of p-type behavior in SeO_(2) has stimulated interest and confusion in the scientific community.In this Letter,we employ density functional theory calculations to reveal the intrinsic intrinsic insulating characteristics of SeO_(2) and highlight the substantial challenges in carrier doping.Our electronic structure analyses indicate that the Se 5^(2) states are energetically positioned too low to effectively interact with the O 2p orbitals,resulting in a valence band maximum(VBM)primarily dominated by the O 2p orbitals.The deep and localized nature of the VBM of SeO_(2) limits its potential as a high-mobility p-type TOS.Defect calculations demonstrate that all intrinsic defects in SeO_(2) exhibit deep transition levels within the bandgap.Regardless of the synthesis conditions,the Fermi level consistently resides in the mid-gap region.Furthermore,deep intrinsic acceptors and donors exhibit negative formation energies in the n-type and p-type regions,respectively,facilitating spontaneous formation and impeding external doping efforts.Thus,the reported p-type conductivity in SeO_(2) samples is unlikely to be intrinsic and is more plausibly attributable to reduced elemental Se,a well-known p-type semiconductor.展开更多
Zinc oxide（ZnO） is a compound semiconductor with a direct band gap and high exciton binding energy.The unique property,i.e.,high efficient light emission at ultraviolet band,makes ZnO potentially applied to the shor...Zinc oxide（ZnO） is a compound semiconductor with a direct band gap and high exciton binding energy.The unique property,i.e.,high efficient light emission at ultraviolet band,makes ZnO potentially applied to the short-wavelength light emitting devices.However,efficient p-type doping is extremely hard for ZnO.Due to the wide band gap and low valence band energy,the self-compensation from donors and high ionization energy of acceptors are the two main problems hindering the enhancement of free hole concentration.Native defects in ZnO can be divided into donor-like and acceptorlike ones.The self-compensation has been found mainly to originate from zinc interstitial and oxygen vacancy related donors.While the acceptor-like defect,zinc vacancy,is thought to be linked to complex shallow acceptors in group-VA doped ZnO.Therefore,the understanding of the behaviors of the native defects is critical to the realization of high-efficient p-type conduction.Meanwhile,some novel ideas have been extensively proposed,like double-acceptor co-doping,acceptor doping in iso-valent element alloyed ZnO,etc.,and have opened new directions for p-type doping.Some of the approaches have been positively judged.In this article,we thus review the recent（2011-now） research progress of the native defects and p-type doping approaches globally.We hope to provide a comprehensive overview and describe a complete picture of the research status of the p-type doping in ZnO for the reference of the researchers in a similar area.展开更多
Zinc oxide （ZnO） is a wide band-gap material of the Ⅱ-Ⅵ group with excellent optical properties for optoelectronics applications, such as the flat panel displays and solar cells used in sports tournament. Despite ...Zinc oxide （ZnO） is a wide band-gap material of the Ⅱ-Ⅵ group with excellent optical properties for optoelectronics applications, such as the flat panel displays and solar cells used in sports tournament. Despite its advantages, the application of ZnO is hampered by the lack of stable p-type doping. In this paper, the recent progress in this field was briefly reviewed, and a comprehensive summary of the research was carded out on ZnO fabrication methods and its electrical, optical, and magnetic properties were presented.展开更多
The electronic structures and optical properties of B3 ZnO series of Zn4X4-yMy（X ：O, S, Se or Te; M = N, Sb, C1 or I; y = 0 or 1） are studied by first-principles calculations using a pseudopotential plane-wave meth...The electronic structures and optical properties of B3 ZnO series of Zn4X4-yMy（X ：O, S, Se or Te; M = N, Sb, C1 or I; y = 0 or 1） are studied by first-principles calculations using a pseudopotential plane-wave method. The results show that Zn d-X p orbital interactions play an important role in the p-type doping tendency in zinc-based Ⅱ-Ⅵ semiconductors. In ZnX, with increasing atomic number of X, Zn d-X p orbital interactions decrease and Zn s-X p orbital interactions increase. Additionally, substituting group-V elements for X will reduce the Zn d-X p orbital interactions while substituting group-VII elements for X will increase the Zn d-X p orbital interactions. The results also show that group-V-doped ZnX and group-Ⅷ-doped ZnX exhibit different optical behaviours due to their different orbital interaction effects.展开更多
The lattice-matched XBn structures of InAsSb,grown on GaSb substrates,exhibit high crystal quali⁃ty,and can achieve extremely low dark currents at high operating temperatures(HOT).Its superior performance is attribute...The lattice-matched XBn structures of InAsSb,grown on GaSb substrates,exhibit high crystal quali⁃ty,and can achieve extremely low dark currents at high operating temperatures(HOT).Its superior performance is attributed to the unipolar barrier,which blocks the majority carriers while allowing unhindered hole transport.To further explore the energy band and carrier transport mechanisms of the XBn unipolar barrier structure,this pa⁃per systematically investigates the influence of doping on the dark current,photocurrent,and tunneling character⁃istics of InAsSb photodetectors in the PBn structure.Three high-quality InAsSb samples with unintentionally doped absorption layers(AL)were prepared,with varying p-type doping concentrations in the GaSb contact layer(CL)and the AlAsSb barrier layer(BL).As the p-type doping concentration in the CL increased,the device’s turn-on bias voltage also increased,and p-type doping in the BL led to tunneling occurring at lower bias voltages.For the sample with UID BL,which exhibited an extremely low dark current of 5×10^(-6) A/cm^(2).The photocurrent characteristics were well-fitted using the back-to-back diode model,revealing the presence of two opposing space charge regions on either side of the BL.展开更多
We investigate the electronic structures and magnetic properties of ZnO doped with N,Cu,and(Cu+N)by using a first principles method and considering the strong correlation effect.It is interesting to compare these thre...We investigate the electronic structures and magnetic properties of ZnO doped with N,Cu,and(Cu+N)by using a first principles method and considering the strong correlation effect.It is interesting to compare these three systems.ZnO:N has weak p-type doping and unstable ferromagnetism,while ZnO:Cu becomes insulating due to the Jahn–Teller effect.Cu and N codoping can not only greatly improve the dopability of p-type doping accompanying the Jahn–Teller fading,but also enhance the ferromagnetism at the same time.The calculation results indicate that there is a win-win effect between N and Cu dopants in the ZnO:(Cu+N)system,which could possibly find applications in spintronics besides optoelectronics.展开更多
Cluster model with DV-Xαmethod is used to study the structural and electronic properties of the p-type doping of ZnSe.It is found that there is Jahn-Teller distortion for P doping and almost no Jahn-Teller distortion...Cluster model with DV-Xαmethod is used to study the structural and electronic properties of the p-type doping of ZnSe.It is found that there is Jahn-Teller distortion for P doping and almost no Jahn-Teller distortion for N doping,and that the impurity levels with respect to the maximum of valence band are 118 and 96meV for N and P doping,respectively.The reasons why N can serve as a better dopant than P for p-type ZnSe are discussed.展开更多
Al-rich nitride,as one of the most important ultra-wide band-gap(UWBG)semiconductors,currently plays the key role of deep ultraviolet(DUV)optoelectronics and potentially possesses the advantages of the huge global inv...Al-rich nitride,as one of the most important ultra-wide band-gap(UWBG)semiconductors,currently plays the key role of deep ultraviolet(DUV)optoelectronics and potentially possesses the advantages of the huge global investment in the manufacturing infrastructure associated with In Ga N material that has become the second most important semiconductor material after Si in the late 2010s[1,2].展开更多
The performance enhancement of MXene/semiconductor heterostructure-based light detectors is greatly restricted by the relatively small junction barrier due to the limited work function of MXenes.The work function of M...The performance enhancement of MXene/semiconductor heterostructure-based light detectors is greatly restricted by the relatively small junction barrier due to the limited work function of MXenes.The work function of MXenes can be largely adjusted to approach 600 meV through simple incorporation of V_(2)O_(5) via a charge transfer doping mechanism.Exploiting this strategy,the performance of MXene/GaN heterostructure-based deep ultraviolet(DUV)photodetectors has been greatly improved.Specifically,the photocurrent is enhanced by nearly 3 times,and the dark current is suppressed at the lowest order of magnitude,resulting in improved responsivity and specific detectivity of 121.6 mA/W and 2.23×10^(13) Jones,respectively,at 265 nm.The device also displays an ultralow dark current of 10^(-14) A,a fast response speed of 0.4 ms/15.1 ms,a large linear dynamic range exceeding 150 dB,and a high DUV/near ultraviolet rejection ratio of 2.41×10^(5).Owing to its good device performance,the detector is capable of sensing weak photon signals produced by a fire flame and functions as an optical receiver to transmit a text signal in a DUV light communication system.The proposed MXene doping method is expected to help develop MXene-based electronic/optoelectronic devices,and the present DUV photodetectors will find potential applications in DUV optoelectronic systems.展开更多
As a catalyst of the air cathode in zinc-air batteries,tungstic acid ferrous(FeWO_(4)),a nanoscale transition metal tungstate,shows a broad application prospect in the oxygen reduction reaction(ORR).While FeWO_(4)poss...As a catalyst of the air cathode in zinc-air batteries,tungstic acid ferrous(FeWO_(4)),a nanoscale transition metal tungstate,shows a broad application prospect in the oxygen reduction reaction(ORR).While FeWO_(4)possesses favorable electrochemical properties and thermodynamic stability,its intrinsic semiconductor characteristics result in a relatively slow electron transfer rate,limiting the ORR catalytic activity.In this work,the electronic structure of FeWO_(4)is significantly modulated by introducing phosphorus(P)atoms with abundant valence electrons.The P doping can adjust the electronic structure of FeWO_(4)and then optimize oxygen-containing intermediates'absorption/desorption efficiency to achieve improved ORR activity.Furthermore,the sodium chloride template is utilized to construct a porous carbon framework for anchoring phosphorus-doped iron tungstate(P-FeWO_(4)/PNC).The porous carbon skeleton provides numerous active sites for the absorption/desorption and redox reactions on the P-FeWO_(4)/PNC surface and serves as mass transport channels for reactants and intermediates.The P-FeWO_(4)/PNC demonstrates ORR performance(E1/2=0.86 V vs.RHE).Furthermore,the zinc-air batteries incorporating the P-FeWO_(4)/PNC composite demonstrate an increased peak power density(172.2 mW·cm^(-2)),high specific capacity(810.1 mAh·g^(-1)),and sustained long-term cycling stability lasting up to 240 h.This research not only contributes to the advancement of cost-effective tungsten-based non-precious metallic ORR catalysts,but also guides their utilization in zinc-air batteries.展开更多
Mn^(2+)-doped CsPbCl_(3)(Mn^(2+):CsPbCl_(3)) nanocrystals(NCs) have attracted considerable attention due to their unique strong and broad orange-red emission band,presenting promising applications in the field of phot...Mn^(2+)-doped CsPbCl_(3)(Mn^(2+):CsPbCl_(3)) nanocrystals(NCs) have attracted considerable attention due to their unique strong and broad orange-red emission band,presenting promising applications in the field of photoelectric devices.However,pristine Mn^(2+):CsPbCl_(3)NCs commonly suffer from low photoluminescence quantum yield(PL QY) and stability issues.Herein,we introduced europium ions(Eu^(3+))into Mn^(2+):CsPbCl_(3)NCs via the thermal injection synthesis method to obtain high performance Eu^(3+)and Mn^(2+)codoped CsPbCl_(3)(Eu^(3+)/Mn^(2+):CsPbCl_(3)) NCs.The maximum PL QY of the resulting Eu^(3+)/Mn^(2+):CsPbCl_(3)NCs reaches up to 90.92%.It is found that the doping of Eu^(3+)ions significantly reduces the non-radiative recombination caused by high defect states,and improves the energy transfer efficiency from exciton to Mn^(2+),thereby boosting the PL performance.Moreover,doping Eu^(3+)ions notably improves the UV-light and water stability of Mn^(2+):CsPbCl_(3)NCs.We further demonstrate the application versatility of Eu^(3+)/Mn^(2+):CsPbCl_(3)NCs in white light emitting diodes(WLEDs) and optical anticounterfeiting applications.This work provides a valuable perspective for the attainment of high performance Mn^(2+):CsPbCl_(3)NCs and lays a foundation for the codoping of other lanthanide ions to adjust the luminescence properties of Mn^(2+):CsPbCl_(3)NCs.展开更多
The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batte...The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batteries.However,its poor cycling,owing to highpressure phase transitions,is one of its disadvantages.In this study,Cu/Ti was introduced into NFM111 cathode material using a solidphase method.Through both theoretically and experimentally,this study found that Cu doping provides a higher redox potential in NFM111,improving its reversible capacity and charge compensation process.The introduction of Ti would enhance the cycling stability of the material,smooth its charge and discharge curves,and suppress its high-voltage phase transitions.Accordingly,the NaNi_(0.27)Fe_(0.28)Mn_(0.33)Cu_(0.05)Ti_(0.06)O_(2)sample used in the study exhibited a remarkable rate performance of 142.97 mAh·g^(-1)at 0.1 C(2.0-4.2 V)and an excellent capacity retention of 72.81%after 300 cycles at 1C(1C=150 mA·g^(-1)).展开更多
This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0...This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.1)Mo_(0.05)O_(3-δ)(B S CNM_(0.05)),Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.05)Mo_(0.1)O_(3-δ)(BSCNM_(0.1)),and Ba_(0.6)Sr_(0.4)Co_(0.85)Mo_(0.15)O_(3-δ)(BSCM)—with Mo doping contents of 5mol%,10mol%,and15mol%,respectively,were successfully prepared using the sol-gel method.The effects of Mo doping on the crystal structure,conductivity,thermal expansion coefficient,oxygen reduction reaction(ORR)activity,and electrochemical performance were systematically evaluated using X-ray diffraction analysis,thermally induced characterization,electrochemical impedance spectroscopy,and single-cell performance tests.The results revealed that Mo doping could improve the conductivity of the materials,suppress their thermal expansion effects,and significantly improve the electrochemical performance.Surface chemical state analysis using X-ray photoelectron spectroscopy revealed that 5mol%Mo doping could facilitate a high adsorbed oxygen concentration leading to enhanced ORR activity in the materials.Density functional theory calculations confirmed that Mo doping promoted the ORR activity in the materials.At an operating temperature of 600℃,the BSCNM_(0.05)cathode material exhibited significantly enhanced electrochemical impedance characteristics,with a reduced area specific resistance of 0.048Ω·cm~2,which was lower than that of the undoped BSCN matrix material by 32.39%.At the same operating temperature,an anode-supported single cell using a BSCNM_(0.05)cathode achieved a peak power density of 1477 mW·cm^(-2),which was 30.71%,56.30%,and 171.50%higher than those of BSCN,BSCNM_(0.1),and B SCM,respectively.The improved ORR activity and electrochemical performance of BSCNM_(0.05)indicate that it can be used as a cathode material in low-temperature solid oxide fuel cells.展开更多
The van der Waals heterostructures have evolved as novel materials for complementing the Si-based semiconductor technologies.Group-10 noble metal dichalcogenides(e.g.,PtS_(2),PtSe_(2),PdS_(2),and PdSe_(2))have been li...The van der Waals heterostructures have evolved as novel materials for complementing the Si-based semiconductor technologies.Group-10 noble metal dichalcogenides(e.g.,PtS_(2),PtSe_(2),PdS_(2),and PdSe_(2))have been listed into two-dimensional(2D)materials toolkit to assemble van der Waals heterostructures.Among them,PdSe_(2) demonstrates advantages of high stability in air,high mobility,and wide tunable bandgap.However,the regulation of p-type doping of PdSe_(2) remains unsolved problem prior to fabricating p–n junction as a fundamental platform of semiconductor physics.Besides,a quantitative method for the controllable doping of PdSe_(2) is yet to be reported.In this study,the doping level of PdSe_(2) was correlated with the concentration of Lewis acids,for example,SnCl_(4),used for soaking.Considering the transfer characteristics,the threshold voltage(the gate voltage corresponding to the minimum drain current)increased after SnCl_(4) soaking treatment.PdSe_(2) transistors were soaked in SnCl_(4) solutions with five different concentrations.The threshold voltages from the as-obtained transfer curves were extracted for linear fitting to the threshold voltage versus doping concentration correlation equation.This study provides in-depth insights into the controllable p-type doping of PdSe_(2).It may also push forward the research of the regulation of conductivity behaviors of 2D materials.展开更多
For zone-melted （ZM） bismuth telluride-based alloys, which are widely commercially available for solidstate cooling and low-temperature power generation around room temperature, introducing point defects is the chie...For zone-melted （ZM） bismuth telluride-based alloys, which are widely commercially available for solidstate cooling and low-temperature power generation around room temperature, introducing point defects is the chief approach to improve their thermoelectric performance. Herein, we report the multiple effects of Se doping on thermoelectric performance of p-type Bi0.5Sb1,5Te3-xSex ＋ 3 wt% Te ZM ingots, which increases carrier concentration, reduces lattice thermal conductivity and deteriorates the carrier mobility. As a result, the peak figure of merit （ZT） is shifted to a higher temperature and a high ZT 1.2 at 350 K is obtained, due to the reduced thermal conductivity and suppressed intrinsic conduction. Further, decreasing Sb content is followed to optimize the room temperature performance and a ZT - 1.1 at 300 K is obtained. These results are significant for designing and optimizing the thermoelectric performance of commercial Bi0.5Sb1.5Te3＋ 3 wt% Te ZM alloys.展开更多
The Zintl compound Mg3Sb2 has been recently identified as promising thermoelectric material owing to its high thermoelectric performance and cost-effective,nontoxicity and environment friendly characteristics.However,...The Zintl compound Mg3Sb2 has been recently identified as promising thermoelectric material owing to its high thermoelectric performance and cost-effective,nontoxicity and environment friendly characteristics.However,the intrinsically p-type Mg3Sb2 shows low figure of merit（z T = 0.23 at 723 K） for its poor electrical conductivity.In this study,a series of Mg（3-x）LixSb2 bulk materials have been prepared by high-energy ball milling and spark plasma sintering（SPS） process.Electrical transport measurements on these materials revealed significant improvement on the power factor with respect to the undoped sample,which can be essentially attributed to the increased carrier concentration,leading to a maximum z T of0.59 at 723 K with the optimum doping level x = 0.01.Additionally,the engineering z T and energy conversion efficiency are calculated to be 0.235 and 4.89%,respectively.To our best knowledge,those are the highest values of all reported p-type Mg3Sb2-based compounds with single element doping.展开更多
Sol--gol method was employed to synthesize Mg doped ZnO films on Si substrates. The annealing temperature-dependent structure and optical property of the produced samples were studied. An interesting result observed i...Sol--gol method was employed to synthesize Mg doped ZnO films on Si substrates. The annealing temperature-dependent structure and optical property of the produced samples were studied. An interesting result observed is that increasing Mg concentration in the studied samples induces the full width at half maximum （FWHM） of their near-band-edge （NBE） emission decrease and the defect related emission of the corresponding sample suppresses drastically. The possible mechanism of the observed result is discussed.展开更多
Nitrogen-doped single-walled carbon nanotubes （CNx-SWNTs） with tunable dopant concentrations were synthesized by chemical vapor deposition （CVD）, and their structure and elemental composition were characterized by...Nitrogen-doped single-walled carbon nanotubes （CNx-SWNTs） with tunable dopant concentrations were synthesized by chemical vapor deposition （CVD）, and their structure and elemental composition were characterized by using transmission electron microscopy （TEM） in combination with electron energy loss spectroscopy （EELS）. By comparing the Raman spectra of pristine and doped nanotubes, we observed the doping-induced Raman G band phonon stiffening and 2D band phonon softening, both of which reflect doping-induced renormalization of the electron and phonon energies in the nan- otubes and behave as expected in accord with the n-type doping effect. On the basis of first principles calculations of the distribution of delocalized carrier density in both the pristine and doped nanotubes, we show how the n-type doping occurs when nitrogen heteroatoms are substitutionally incorporated into the honeycomb tube-shell carbon lattice.展开更多
BiSbSe_(3) is an intrinsic n-type thermoelectric material,which attracts a lot of research interest due to its low lattice thermal conductivity and multiple band structure,and it exhibits excellent thermoelectric prop...BiSbSe_(3) is an intrinsic n-type thermoelectric material,which attracts a lot of research interest due to its low lattice thermal conductivity and multiple band structure,and it exhibits excellent thermoelectric properties in the midtemperature region.However,there is little research on p-type BiSbSe_(3).This work realized the successful preparation of p-type BiSbSe_(3) through Pb doping.The thermoelectric transport properties of Pb-doped p-type BiSbSe_(3)were investigated.Pb doping could further reduce the thermal conductivity of BiSbSe_(3).All Pb-doped samples exhibited and maintained stable p-type transmissionthroughout the working temperature range(300-723 K).This work proves that Pb can be successfully used as a p-type dopant for BiSbSe_(3).展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.52372150,12088101,and 11991060)the National Key R&D Program of China(Grant No.2022YFB4200305)。
文摘Wide-bandgap two-dimensional (2D) β-TeO_(2) has been reported as a high-mobility p-type transparent semiconductor [Nat. Electron. 4 277 (2021)], attracting significant attention. This "breakthrough" not only challenges the conventional characterization of TeO_(2) as an insulator but also conflicts with the anticipated difficulty in hole doping of TeO_(2) by established chemical trends. Notably, the reported Fermi level of 0.9 eV above the valence band maximum actually suggests that the material is an insulator, contradicting the high hole density obtained by Hall effect measurement. Furthermore, the detected residual Se and the possible reduced elemental Te in the 2D β-TeO_(2) samples introduces complexity, considering that elemental Se, Te, and Te_(1−x)Se_(x) themselves are high-mobility p-type semiconductors. Therefore, doubts regarding the true cause of the p-type conductivity observed in the 2D β-TeO_(2) samples arise. In this Letter, we employ density functional theory calculations to illustrate that TeO_(2), whether in its bulk forms of α-, β-, or γ-TeO_(2), or in the 2D β-TeO_(2) nanosheets, inherently exhibits insulating properties and poses challenges in carrier doping due to its shallow conduction band minimum and deep valence band maximum. Our findings shed light on the insulating properties and doping difficulty of TeO_(2), contrasting with the claimed p-type conductivity in the 2D β-TeO_(2) samples, prompting inquiries into the true origin of the p-type conductivity.
基金financially supported by the National Natural Science Foundation of China(Grant No.52372150)。
文摘p-type transparent oxide semiconductors(TOSs)are significant in the semiconductor industry,driving advancements in optoelectronic technologies for transparent electronic devices with unique properties.The recent discovery of p-type behavior in SeO_(2) has stimulated interest and confusion in the scientific community.In this Letter,we employ density functional theory calculations to reveal the intrinsic intrinsic insulating characteristics of SeO_(2) and highlight the substantial challenges in carrier doping.Our electronic structure analyses indicate that the Se 5^(2) states are energetically positioned too low to effectively interact with the O 2p orbitals,resulting in a valence band maximum(VBM)primarily dominated by the O 2p orbitals.The deep and localized nature of the VBM of SeO_(2) limits its potential as a high-mobility p-type TOS.Defect calculations demonstrate that all intrinsic defects in SeO_(2) exhibit deep transition levels within the bandgap.Regardless of the synthesis conditions,the Fermi level consistently resides in the mid-gap region.Furthermore,deep intrinsic acceptors and donors exhibit negative formation energies in the n-type and p-type regions,respectively,facilitating spontaneous formation and impeding external doping efforts.Thus,the reported p-type conductivity in SeO_(2) samples is unlikely to be intrinsic and is more plausibly attributable to reduced elemental Se,a well-known p-type semiconductor.
基金Project supported by the State Key Program for Basic Research of China(Grant No.2011CB302003)the National Natural Science Foundation of China(Grant Nos.61274058,61322403,61504057,and 61574075)+1 种基金the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK20130013 and BK20150585)the Six Talent Peaks Project in Jiangsu Province,China(Grant No.2014XXRJ001)
文摘Zinc oxide（ZnO） is a compound semiconductor with a direct band gap and high exciton binding energy.The unique property,i.e.,high efficient light emission at ultraviolet band,makes ZnO potentially applied to the short-wavelength light emitting devices.However,efficient p-type doping is extremely hard for ZnO.Due to the wide band gap and low valence band energy,the self-compensation from donors and high ionization energy of acceptors are the two main problems hindering the enhancement of free hole concentration.Native defects in ZnO can be divided into donor-like and acceptorlike ones.The self-compensation has been found mainly to originate from zinc interstitial and oxygen vacancy related donors.While the acceptor-like defect,zinc vacancy,is thought to be linked to complex shallow acceptors in group-VA doped ZnO.Therefore,the understanding of the behaviors of the native defects is critical to the realization of high-efficient p-type conduction.Meanwhile,some novel ideas have been extensively proposed,like double-acceptor co-doping,acceptor doping in iso-valent element alloyed ZnO,etc.,and have opened new directions for p-type doping.Some of the approaches have been positively judged.In this article,we thus review the recent（2011-now） research progress of the native defects and p-type doping approaches globally.We hope to provide a comprehensive overview and describe a complete picture of the research status of the p-type doping in ZnO for the reference of the researchers in a similar area.
基金Funded by the National Social Science Fund Project(No.2012BTY014)
文摘Zinc oxide （ZnO） is a wide band-gap material of the Ⅱ-Ⅵ group with excellent optical properties for optoelectronics applications, such as the flat panel displays and solar cells used in sports tournament. Despite its advantages, the application of ZnO is hampered by the lack of stable p-type doping. In this paper, the recent progress in this field was briefly reviewed, and a comprehensive summary of the research was carded out on ZnO fabrication methods and its electrical, optical, and magnetic properties were presented.
基金Project supported by the National Natural Science Foundation of China （Grant No 10625416）.
文摘The electronic structures and optical properties of B3 ZnO series of Zn4X4-yMy（X ：O, S, Se or Te; M = N, Sb, C1 or I; y = 0 or 1） are studied by first-principles calculations using a pseudopotential plane-wave method. The results show that Zn d-X p orbital interactions play an important role in the p-type doping tendency in zinc-based Ⅱ-Ⅵ semiconductors. In ZnX, with increasing atomic number of X, Zn d-X p orbital interactions decrease and Zn s-X p orbital interactions increase. Additionally, substituting group-V elements for X will reduce the Zn d-X p orbital interactions while substituting group-VII elements for X will increase the Zn d-X p orbital interactions. The results also show that group-V-doped ZnX and group-Ⅷ-doped ZnX exhibit different optical behaviours due to their different orbital interaction effects.
基金Supported by the Candidate Talents Training Fund of Yunnan Province(202205AC160054)the National Natural Science Foundation of China(62174156)。
文摘The lattice-matched XBn structures of InAsSb,grown on GaSb substrates,exhibit high crystal quali⁃ty,and can achieve extremely low dark currents at high operating temperatures(HOT).Its superior performance is attributed to the unipolar barrier,which blocks the majority carriers while allowing unhindered hole transport.To further explore the energy band and carrier transport mechanisms of the XBn unipolar barrier structure,this pa⁃per systematically investigates the influence of doping on the dark current,photocurrent,and tunneling character⁃istics of InAsSb photodetectors in the PBn structure.Three high-quality InAsSb samples with unintentionally doped absorption layers(AL)were prepared,with varying p-type doping concentrations in the GaSb contact layer(CL)and the AlAsSb barrier layer(BL).As the p-type doping concentration in the CL increased,the device’s turn-on bias voltage also increased,and p-type doping in the BL led to tunneling occurring at lower bias voltages.For the sample with UID BL,which exhibited an extremely low dark current of 5×10^(-6) A/cm^(2).The photocurrent characteristics were well-fitted using the back-to-back diode model,revealing the presence of two opposing space charge regions on either side of the BL.
基金Supported by the Project of Cultivating Innovative Talents for Colleges&Universities of Henan Province under Grant No 2002006the Natural Science Foundation of Department of Education of Henan Province under Grant No 2009B48003the Key Technologies R&D Program of Henan Province under Grant No 092102210005.
文摘We investigate the electronic structures and magnetic properties of ZnO doped with N,Cu,and(Cu+N)by using a first principles method and considering the strong correlation effect.It is interesting to compare these three systems.ZnO:N has weak p-type doping and unstable ferromagnetism,while ZnO:Cu becomes insulating due to the Jahn–Teller effect.Cu and N codoping can not only greatly improve the dopability of p-type doping accompanying the Jahn–Teller fading,but also enhance the ferromagnetism at the same time.The calculation results indicate that there is a win-win effect between N and Cu dopants in the ZnO:(Cu+N)system,which could possibly find applications in spintronics besides optoelectronics.
基金Supported by the'863'High Technology Program of China.
文摘Cluster model with DV-Xαmethod is used to study the structural and electronic properties of the p-type doping of ZnSe.It is found that there is Jahn-Teller distortion for P doping and almost no Jahn-Teller distortion for N doping,and that the impurity levels with respect to the maximum of valence band are 118 and 96meV for N and P doping,respectively.The reasons why N can serve as a better dopant than P for p-type ZnSe are discussed.
文摘Al-rich nitride,as one of the most important ultra-wide band-gap(UWBG)semiconductors,currently plays the key role of deep ultraviolet(DUV)optoelectronics and potentially possesses the advantages of the huge global investment in the manufacturing infrastructure associated with In Ga N material that has become the second most important semiconductor material after Si in the late 2010s[1,2].
基金financially supported by the National Natural Science Foundation of China(NSFC,62275002,51902078)the Anhui Provincial Natural Science Foundation(2008085MF205)the Fundamental Research Funds for the Central Universities(JZ2020HGTB0051)。
文摘The performance enhancement of MXene/semiconductor heterostructure-based light detectors is greatly restricted by the relatively small junction barrier due to the limited work function of MXenes.The work function of MXenes can be largely adjusted to approach 600 meV through simple incorporation of V_(2)O_(5) via a charge transfer doping mechanism.Exploiting this strategy,the performance of MXene/GaN heterostructure-based deep ultraviolet(DUV)photodetectors has been greatly improved.Specifically,the photocurrent is enhanced by nearly 3 times,and the dark current is suppressed at the lowest order of magnitude,resulting in improved responsivity and specific detectivity of 121.6 mA/W and 2.23×10^(13) Jones,respectively,at 265 nm.The device also displays an ultralow dark current of 10^(-14) A,a fast response speed of 0.4 ms/15.1 ms,a large linear dynamic range exceeding 150 dB,and a high DUV/near ultraviolet rejection ratio of 2.41×10^(5).Owing to its good device performance,the detector is capable of sensing weak photon signals produced by a fire flame and functions as an optical receiver to transmit a text signal in a DUV light communication system.The proposed MXene doping method is expected to help develop MXene-based electronic/optoelectronic devices,and the present DUV photodetectors will find potential applications in DUV optoelectronic systems.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.22178148 and 22278193)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘As a catalyst of the air cathode in zinc-air batteries,tungstic acid ferrous(FeWO_(4)),a nanoscale transition metal tungstate,shows a broad application prospect in the oxygen reduction reaction(ORR).While FeWO_(4)possesses favorable electrochemical properties and thermodynamic stability,its intrinsic semiconductor characteristics result in a relatively slow electron transfer rate,limiting the ORR catalytic activity.In this work,the electronic structure of FeWO_(4)is significantly modulated by introducing phosphorus(P)atoms with abundant valence electrons.The P doping can adjust the electronic structure of FeWO_(4)and then optimize oxygen-containing intermediates'absorption/desorption efficiency to achieve improved ORR activity.Furthermore,the sodium chloride template is utilized to construct a porous carbon framework for anchoring phosphorus-doped iron tungstate(P-FeWO_(4)/PNC).The porous carbon skeleton provides numerous active sites for the absorption/desorption and redox reactions on the P-FeWO_(4)/PNC surface and serves as mass transport channels for reactants and intermediates.The P-FeWO_(4)/PNC demonstrates ORR performance(E1/2=0.86 V vs.RHE).Furthermore,the zinc-air batteries incorporating the P-FeWO_(4)/PNC composite demonstrate an increased peak power density(172.2 mW·cm^(-2)),high specific capacity(810.1 mAh·g^(-1)),and sustained long-term cycling stability lasting up to 240 h.This research not only contributes to the advancement of cost-effective tungsten-based non-precious metallic ORR catalysts,but also guides their utilization in zinc-air batteries.
基金Project supported by the National Natural Science Foundation of China (12174075)the Scientific and Technological Bases and Talents of Guangxi (Guike AD21220016)+1 种基金Guangxi Science and Technology Major Project(AA23073018)the special fund for Guangxi Bagui Scholars。
文摘Mn^(2+)-doped CsPbCl_(3)(Mn^(2+):CsPbCl_(3)) nanocrystals(NCs) have attracted considerable attention due to their unique strong and broad orange-red emission band,presenting promising applications in the field of photoelectric devices.However,pristine Mn^(2+):CsPbCl_(3)NCs commonly suffer from low photoluminescence quantum yield(PL QY) and stability issues.Herein,we introduced europium ions(Eu^(3+))into Mn^(2+):CsPbCl_(3)NCs via the thermal injection synthesis method to obtain high performance Eu^(3+)and Mn^(2+)codoped CsPbCl_(3)(Eu^(3+)/Mn^(2+):CsPbCl_(3)) NCs.The maximum PL QY of the resulting Eu^(3+)/Mn^(2+):CsPbCl_(3)NCs reaches up to 90.92%.It is found that the doping of Eu^(3+)ions significantly reduces the non-radiative recombination caused by high defect states,and improves the energy transfer efficiency from exciton to Mn^(2+),thereby boosting the PL performance.Moreover,doping Eu^(3+)ions notably improves the UV-light and water stability of Mn^(2+):CsPbCl_(3)NCs.We further demonstrate the application versatility of Eu^(3+)/Mn^(2+):CsPbCl_(3)NCs in white light emitting diodes(WLEDs) and optical anticounterfeiting applications.This work provides a valuable perspective for the attainment of high performance Mn^(2+):CsPbCl_(3)NCs and lays a foundation for the codoping of other lanthanide ions to adjust the luminescence properties of Mn^(2+):CsPbCl_(3)NCs.
基金supported by the Low-Cost Long-Life Batteries program,China(No.WL-24-08-01)the National Natural Science Foundation of China(No.22279007)。
文摘The outstanding performance of O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NFM111)at both high and low temperatures coupled with its impressive specific capacity makes it an excellent cathode material for sodium-ion batteries.However,its poor cycling,owing to highpressure phase transitions,is one of its disadvantages.In this study,Cu/Ti was introduced into NFM111 cathode material using a solidphase method.Through both theoretically and experimentally,this study found that Cu doping provides a higher redox potential in NFM111,improving its reversible capacity and charge compensation process.The introduction of Ti would enhance the cycling stability of the material,smooth its charge and discharge curves,and suppress its high-voltage phase transitions.Accordingly,the NaNi_(0.27)Fe_(0.28)Mn_(0.33)Cu_(0.05)Ti_(0.06)O_(2)sample used in the study exhibited a remarkable rate performance of 142.97 mAh·g^(-1)at 0.1 C(2.0-4.2 V)and an excellent capacity retention of 72.81%after 300 cycles at 1C(1C=150 mA·g^(-1)).
基金financially supported by the National Natural Science Foundation of China(No.22309067)the Open Project Program of the State Key Laboratory of Materials-Oriented Chemical Engineering,China(No.KL21-05)the Marine Equipment and Technology Institute,Jiangsu University of Science and Technology,China(No.XTCX202404)。
文摘This study focused on improving the cathode performance of Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.15)O_(3-δ)(BSCN)-based perovskite materials through molybdenum(Mo)doping.Pure BSCN and Mo-modified-BSCN—Ea_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.1)Mo_(0.05)O_(3-δ)(B S CNM_(0.05)),Ba_(0.6)Sr_(0.4)Co_(0.85)Nb_(0.05)Mo_(0.1)O_(3-δ)(BSCNM_(0.1)),and Ba_(0.6)Sr_(0.4)Co_(0.85)Mo_(0.15)O_(3-δ)(BSCM)—with Mo doping contents of 5mol%,10mol%,and15mol%,respectively,were successfully prepared using the sol-gel method.The effects of Mo doping on the crystal structure,conductivity,thermal expansion coefficient,oxygen reduction reaction(ORR)activity,and electrochemical performance were systematically evaluated using X-ray diffraction analysis,thermally induced characterization,electrochemical impedance spectroscopy,and single-cell performance tests.The results revealed that Mo doping could improve the conductivity of the materials,suppress their thermal expansion effects,and significantly improve the electrochemical performance.Surface chemical state analysis using X-ray photoelectron spectroscopy revealed that 5mol%Mo doping could facilitate a high adsorbed oxygen concentration leading to enhanced ORR activity in the materials.Density functional theory calculations confirmed that Mo doping promoted the ORR activity in the materials.At an operating temperature of 600℃,the BSCNM_(0.05)cathode material exhibited significantly enhanced electrochemical impedance characteristics,with a reduced area specific resistance of 0.048Ω·cm~2,which was lower than that of the undoped BSCN matrix material by 32.39%.At the same operating temperature,an anode-supported single cell using a BSCNM_(0.05)cathode achieved a peak power density of 1477 mW·cm^(-2),which was 30.71%,56.30%,and 171.50%higher than those of BSCN,BSCNM_(0.1),and B SCM,respectively.The improved ORR activity and electrochemical performance of BSCNM_(0.05)indicate that it can be used as a cathode material in low-temperature solid oxide fuel cells.
基金the Natural Science Foundation of Shandong Province for Excellent Young Scholars(No.ZR2022YQ41)the fund(No.SKT2203)from the State Key Laboratories of Transducer Technology,Shanghai Institute of Microsystem and Information Technology+9 种基金Chinese Academy of Sciences for support.This work was partially supported by the National Key Research and Development Program of China(No.2022YFE0124200)the National Natural Science Foundation of China(No.U2241221)W.J.Z.thanks the Major innovation project of Shandong Province(No.2021CXGC010603)the National Natural Science Foundation of China(No.52022037)the Taishan Scholars Project Special Funds(No.TSQN201812083)The project was supported by the Foundation(No.GZKF202107)of State Key Laboratory of Biobased Material and Green PapermakingQilu University of Technology,Shandong Academy of Sciences.M.H.R.thanks the National Natural Science Foundation of China(No.52071225)the National Science Center and the Czech Republic under the ERDF program“Institute of Environmental Technology-Excellent Research”(No.CZ.02.1.01/0.0/0.0/16_019/0000853)the Sino-German Research Institute(No.GZ 1400)for supportS.X.H.thanks the National Natural Science Foundation of China(Nos.21976014 and 22276013)for funding,and thanks the Tianhe2-JK HPC for generous computer time.
文摘The van der Waals heterostructures have evolved as novel materials for complementing the Si-based semiconductor technologies.Group-10 noble metal dichalcogenides(e.g.,PtS_(2),PtSe_(2),PdS_(2),and PdSe_(2))have been listed into two-dimensional(2D)materials toolkit to assemble van der Waals heterostructures.Among them,PdSe_(2) demonstrates advantages of high stability in air,high mobility,and wide tunable bandgap.However,the regulation of p-type doping of PdSe_(2) remains unsolved problem prior to fabricating p–n junction as a fundamental platform of semiconductor physics.Besides,a quantitative method for the controllable doping of PdSe_(2) is yet to be reported.In this study,the doping level of PdSe_(2) was correlated with the concentration of Lewis acids,for example,SnCl_(4),used for soaking.Considering the transfer characteristics,the threshold voltage(the gate voltage corresponding to the minimum drain current)increased after SnCl_(4) soaking treatment.PdSe_(2) transistors were soaked in SnCl_(4) solutions with five different concentrations.The threshold voltages from the as-obtained transfer curves were extracted for linear fitting to the threshold voltage versus doping concentration correlation equation.This study provides in-depth insights into the controllable p-type doping of PdSe_(2).It may also push forward the research of the regulation of conductivity behaviors of 2D materials.
基金supported by the National Natural Science Foundation of China (Nos. 61534001 and 11574267)the National Science Fund for Distinguished Young Scholars (No.51725102)
文摘For zone-melted （ZM） bismuth telluride-based alloys, which are widely commercially available for solidstate cooling and low-temperature power generation around room temperature, introducing point defects is the chief approach to improve their thermoelectric performance. Herein, we report the multiple effects of Se doping on thermoelectric performance of p-type Bi0.5Sb1,5Te3-xSex ＋ 3 wt% Te ZM ingots, which increases carrier concentration, reduces lattice thermal conductivity and deteriorates the carrier mobility. As a result, the peak figure of merit （ZT） is shifted to a higher temperature and a high ZT 1.2 at 350 K is obtained, due to the reduced thermal conductivity and suppressed intrinsic conduction. Further, decreasing Sb content is followed to optimize the room temperature performance and a ZT - 1.1 at 300 K is obtained. These results are significant for designing and optimizing the thermoelectric performance of commercial Bi0.5Sb1.5Te3＋ 3 wt% Te ZM alloys.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1601213 and 51572287)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Grant No.QYZDB-SSW-SLH013)
文摘The Zintl compound Mg3Sb2 has been recently identified as promising thermoelectric material owing to its high thermoelectric performance and cost-effective,nontoxicity and environment friendly characteristics.However,the intrinsically p-type Mg3Sb2 shows low figure of merit（z T = 0.23 at 723 K） for its poor electrical conductivity.In this study,a series of Mg（3-x）LixSb2 bulk materials have been prepared by high-energy ball milling and spark plasma sintering（SPS） process.Electrical transport measurements on these materials revealed significant improvement on the power factor with respect to the undoped sample,which can be essentially attributed to the increased carrier concentration,leading to a maximum z T of0.59 at 723 K with the optimum doping level x = 0.01.Additionally,the engineering z T and energy conversion efficiency are calculated to be 0.235 and 4.89%,respectively.To our best knowledge,those are the highest values of all reported p-type Mg3Sb2-based compounds with single element doping.
文摘Sol--gol method was employed to synthesize Mg doped ZnO films on Si substrates. The annealing temperature-dependent structure and optical property of the produced samples were studied. An interesting result observed is that increasing Mg concentration in the studied samples induces the full width at half maximum （FWHM） of their near-band-edge （NBE） emission decrease and the defect related emission of the corresponding sample suppresses drastically. The possible mechanism of the observed result is discussed.
基金supported by the National Natural Science Foundation of China(Grant Nos.11004230,51172273,11290161,and 11027402)the National Key Basic Research Program of China(Grant Nos.2012CB933003 and 2013CB932603)the Innovative Project of the Chinese Academy of Sciences(GrantNo.KJCX2-YW-W35)
文摘Nitrogen-doped single-walled carbon nanotubes （CNx-SWNTs） with tunable dopant concentrations were synthesized by chemical vapor deposition （CVD）, and their structure and elemental composition were characterized by using transmission electron microscopy （TEM） in combination with electron energy loss spectroscopy （EELS）. By comparing the Raman spectra of pristine and doped nanotubes, we observed the doping-induced Raman G band phonon stiffening and 2D band phonon softening, both of which reflect doping-induced renormalization of the electron and phonon energies in the nan- otubes and behave as expected in accord with the n-type doping effect. On the basis of first principles calculations of the distribution of delocalized carrier density in both the pristine and doped nanotubes, we show how the n-type doping occurs when nitrogen heteroatoms are substitutionally incorporated into the honeycomb tube-shell carbon lattice.
基金financially supported by the National Natural Science Foundation of China (Nos.52002011,51571007,and 51772012)the National Key Research and Development Program of China (No.2021YFB3201100)+4 种基金the National Key Research and Development Program of China (No.2018YFA0702100)Beijing Natural Science Foundation (No.JQ18004)111 Project (No.B17002)the National Science Fund for Distinguished Young Scholars (No.51925101)the Opening Project of State Key Laboratory of High Performance Ceramics and Superfine Microstructure (No.SKL202005SIC)。
文摘BiSbSe_(3) is an intrinsic n-type thermoelectric material,which attracts a lot of research interest due to its low lattice thermal conductivity and multiple band structure,and it exhibits excellent thermoelectric properties in the midtemperature region.However,there is little research on p-type BiSbSe_(3).This work realized the successful preparation of p-type BiSbSe_(3) through Pb doping.The thermoelectric transport properties of Pb-doped p-type BiSbSe_(3)were investigated.Pb doping could further reduce the thermal conductivity of BiSbSe_(3).All Pb-doped samples exhibited and maintained stable p-type transmissionthroughout the working temperature range(300-723 K).This work proves that Pb can be successfully used as a p-type dopant for BiSbSe_(3).
