Surface passivation via post-treatment with organic reagents is a popular strategy to improve the stability and efficiency of perovskite solar cell. However, organic passivation still suffers from the weak bonding bet...Surface passivation via post-treatment with organic reagents is a popular strategy to improve the stability and efficiency of perovskite solar cell. However, organic passivation still suffers from the weak bonding between organic chemicals and perovskite layers. Here we reported a facile inorganic layer passivating method containing strong Pb–S bonding by using ammonium sulfide treatment. A compact PbS_x layer was in-situ formed on the top surface of the perovskite film, which could passivate and protect the perovskite surface to enhance the performance and stability. Our novel inorganic passivation layer strategy demonstrates great potential for the development of high efficiency hybrid and robust perovskite optoelectronics.展开更多
The exploitation of fossil resources to meet humanity’s energy needs is the root cause of the climate warming phenomenon facing the planet. In this context, non-carbon-based energies, such as photovoltaic energy, are...The exploitation of fossil resources to meet humanity’s energy needs is the root cause of the climate warming phenomenon facing the planet. In this context, non-carbon-based energies, such as photovoltaic energy, are identified as crucial solutions. Organic perovskites MAPbI<sub>3</sub> and FAPbI<sub>3</sub>, characterized by their abundance, low cost, and ease of synthesis, are emerging as candidates for study to enhance their competitiveness. It is within this framework that this article presents a comparative analysis of the performances of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> perovskites in the context of photovoltaic devices. The analysis focuses on the optoelectronic characteristics and stability of these high-potential materials. The optical properties of perovskites are rigorously evaluated, including band gaps, photoluminescence, and light absorption, using UV-Vis spectroscopy and photoluminescence techniques. The crystal structure is characterized by X-ray diffraction, while film morphology is examined through scanning electron microscopy. The results reveal significant variations between the two types of perovskites, directly impacting the performance of resulting solar devices. Simultaneously, the stability of perovskites is subjected to a thorough study, exposing the materials to various environmental conditions, highlighting key determinants of their durability. Films of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> demonstrate distinct differences in terms of topography, optical performance, and stability. Research has unveiled that planar perovskite solar cells based on FAPbI<sub>3</sub> offer higher photoelectric conversion efficiency, surpassing their MAPbI<sub>3</sub>-based counterparts in terms of performance. These advancements aim to overcome stability constraints and enhance the long-term durability of perovskites, ultimately aiming for practical application of these materials. This comprehensive comparative analysis provides an enlightened understanding of the optoelectronic performance and stability of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> perovskites, which is critically important to guide future research and development of solar devices that are both more efficient and sustainable.展开更多
Using the spray pyrolysis process,the work shows the production of pristine and 6%Ag-doped methylammonium lead iodide bromide(MAPbI2Br)film.Through X-ray diffraction analysis,it was found that Ag doping led to a signi...Using the spray pyrolysis process,the work shows the production of pristine and 6%Ag-doped methylammonium lead iodide bromide(MAPbI2Br)film.Through X-ray diffraction analysis,it was found that Ag doping led to a significant increase in grain size to 29.64 nm,alongside reductions in dislocation line density to 5.39×1014 m−2 and d-spacing to 3.18Å,while maintaining the native cubic crystal structure of MAPbI2Br.This research demonstrates a reduction in deep-level trap states with Ag doping,along with a significant narrowing of the band gap to 1.91 eV in the 6%Ag-doped MAPbI2Br.Moreover,the refractive index and extinction coefficient increased to 2.54 and 2.13,respectively.Regarding solar cell performance,all cells demonstrated encouraging outcomes;still,the 6%Ag-doped cell distinguished itself with a fill factor of 0.82,an open-circuit voltage of 1.07 V,an outstanding short-circuit current density of 11.31 mA/cm²,and an efficiency of 10.03%.These results highlight the effectiveness of Ag doping in improving perovskite solar cell technology,marking a notable progress in this field.展开更多
Time-of-flight(ToF)transient current method is an important technique to study the transport characteristics of semiconductors.Here,both the direct current(DC)and pulsed bias ToF transient current method are employed ...Time-of-flight(ToF)transient current method is an important technique to study the transport characteristics of semiconductors.Here,both the direct current(DC)and pulsed bias ToF transient current method are employed to investigate the transport properties and electric field distribution inside the MAPbI_(3) single crystal detector.Owing to the almost homogeneous electric field built inside the detector during pulsed bias ToF measurement,the free hole mobility can be directly calculated to be about 22 cm^(2)·V^(-1)·s^(-1),and the hole lifetime is around 6.5μs–17.5μs.Hence,the mobility-lifetime product can be derived to be 1.4×10^(-4)cm^(2)·V^(-1)–3.9×10^(-4)cm^(2)·V^(-1).The transit time measured under the DC bias deviates with increasing voltage compared with that under the pulsed bias,which arises mainly from the inhomogeneous electric field distribution inside the perovskite.The positive space charge density can then be deduced to increase from 3.1×10^(10)cm^(-3)to 6.89×10^(10)cm^(-3)in a bias range of 50 V–150 V.The ToF measurement can provide us with a facile way to accurately measure the transport properties of the perovskite single crystals,and is also helpful in obtaining a rough picture of the internal electric field distribution.展开更多
Using the spray pyrolysis process,the work shows the production of pristine and 6%Ag-doped methylammonium lead iodide bromide(MAPbI2Br)film.Through X-ray diffraction analysis,it was found that Ag doping led to a signi...Using the spray pyrolysis process,the work shows the production of pristine and 6%Ag-doped methylammonium lead iodide bromide(MAPbI2Br)film.Through X-ray diffraction analysis,it was found that Ag doping led to a significant increase in grain size to 29.64 nm,alongside reductions in dislocation line density to 5.39×1014 m−2 and d-spacing to 3.18Å,while maintaining the native cubic crystal structure of MAPbI2Br.This research demonstrates a reduction in deep-level trap states with Ag doping,along with a significant narrowing of the band gap to 1.91 eV in the 6%Ag-doped MAPbI2Br.Moreover,the refractive index and extinction coefficient increased to 2.54 and 2.13,respectively.Regarding solar cell performance,all cells demonstrated encouraging outcomes;still,the 6%Ag-doped cell distinguished itself with a fill factor of 0.82,an open-circuit voltage of 1.07 V,an outstanding short-circuit current density of 11.31 mA/cm²,and an efficiency of 10.03%.These results highlight the effectiveness of Ag doping in improving perovskite solar cell technology,marking a notable progress in this field.展开更多
The strong coupling between photons and phonons in polar materials gives rise to phonon-polaritons that encapsulate a wealth of physical information,offering crucial tools for the ultrafast terahertz sources and the t...The strong coupling between photons and phonons in polar materials gives rise to phonon-polaritons that encapsulate a wealth of physical information,offering crucial tools for the ultrafast terahertz sources and the topological engineering of terahertz light.However,it is still quite challenging to form and manipulate the terahertz phonon-polaritons under the ultrastrong coupling regime till now.In this work,we demonstrate the ultrastrong coupling between the phonon(at 0.95 THz)in a MAPbI3 film and the metallic bound states in the continuum(BICs)in Au metasurfaces.The Rabi splitting can be continuously tuned from 28%to 48.4%of the phonon frequency by adjusting the parameters(size,shape and period)of Au metasurfaces,reaching the ultrastrong coupling regime.By introducing wavelet transform,the mode evolution information of the terahertz phonon-polariton is successfully extracted.It indicates that the phonon radiation intensity of the MAPbI_(3)film is enhanced as the coupling strength is increased.This work not only establishes a new platform for terahertz devices but also opens new avenues for exploring the intricate dynamics of terahertz phonon-polaritons.展开更多
Organic–inorganic hybrid perovskites are quite promising candidates in the field of electromagnetic wave (EMW) absorption due to their unique physicochemical properties. However, it is still a considerable challenge ...Organic–inorganic hybrid perovskites are quite promising candidates in the field of electromagnetic wave (EMW) absorption due to their unique physicochemical properties. However, it is still a considerable challenge to satisfy the light weight, broad bandwidth, and strong absorption properties simultaneously. Herein, the solution of methylammonium lead iodide (MAPbI3) perovskites was infiltrated into the pores of reduced graphene oxide (rGO) aerogels. After drying, a series of MAPbI3/rGO composite aerogel (MGA) materials were synthesized by anchoring the MAPbI3 perovskite nanoparticles to rGO sheets with the assistance of rGO templates. Through the adjustment of component ratios, excellent EMW absorption properties are obtained with the synergistic effects of polarization loss, conduction loss, and multiple reflection and scattering of MAPbI3 and rGO. The porous structure of the aerogel and the suitable group distribution ratio allowed the MGA-4 samples to obtain excellent impedance matching and ultra-low density of ∼ 7.69 mg·cm−3. At a low filling ratio of 15 wt.%, the MGA-4 sample simultaneously achieves highly efficient and broadband EMW absorption performance at a thin thickness. The MGA-4 sample obtained a minimum reflection loss value of −64.35 dB and the effective absorption bandwidth (EAB) value of 5.4 GHz at a thickness of 2.08 mm and a maximum EAB (EABmax) value of 6.2 GHz under 2.22 mm. The MGA-5 sample obtained a maximum EAB value of 6.4 GHz with the thinckness of 2.16 mm. Furthermore, the simulation results of the radar cross-section (RCS) verified the component-optimized composites are capable of achieving excellent EMW attenuation. This paper provides a new approach and valuable reference for the development of hybrid perovskite-based microwave absorption materials with lightweight, ultra-broadband, and strong absorption properties.展开更多
基金the support of the NSFC (Grant 21777096 and 51861145101)Huoyingdong Grant (151046)+1 种基金the support of the Initiative Postdocs Supporting Program (Grant No.BX20180185)China Postdoctoral Science Foundation (Grant No.2018M640387)。
文摘Surface passivation via post-treatment with organic reagents is a popular strategy to improve the stability and efficiency of perovskite solar cell. However, organic passivation still suffers from the weak bonding between organic chemicals and perovskite layers. Here we reported a facile inorganic layer passivating method containing strong Pb–S bonding by using ammonium sulfide treatment. A compact PbS_x layer was in-situ formed on the top surface of the perovskite film, which could passivate and protect the perovskite surface to enhance the performance and stability. Our novel inorganic passivation layer strategy demonstrates great potential for the development of high efficiency hybrid and robust perovskite optoelectronics.
文摘The exploitation of fossil resources to meet humanity’s energy needs is the root cause of the climate warming phenomenon facing the planet. In this context, non-carbon-based energies, such as photovoltaic energy, are identified as crucial solutions. Organic perovskites MAPbI<sub>3</sub> and FAPbI<sub>3</sub>, characterized by their abundance, low cost, and ease of synthesis, are emerging as candidates for study to enhance their competitiveness. It is within this framework that this article presents a comparative analysis of the performances of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> perovskites in the context of photovoltaic devices. The analysis focuses on the optoelectronic characteristics and stability of these high-potential materials. The optical properties of perovskites are rigorously evaluated, including band gaps, photoluminescence, and light absorption, using UV-Vis spectroscopy and photoluminescence techniques. The crystal structure is characterized by X-ray diffraction, while film morphology is examined through scanning electron microscopy. The results reveal significant variations between the two types of perovskites, directly impacting the performance of resulting solar devices. Simultaneously, the stability of perovskites is subjected to a thorough study, exposing the materials to various environmental conditions, highlighting key determinants of their durability. Films of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> demonstrate distinct differences in terms of topography, optical performance, and stability. Research has unveiled that planar perovskite solar cells based on FAPbI<sub>3</sub> offer higher photoelectric conversion efficiency, surpassing their MAPbI<sub>3</sub>-based counterparts in terms of performance. These advancements aim to overcome stability constraints and enhance the long-term durability of perovskites, ultimately aiming for practical application of these materials. This comprehensive comparative analysis provides an enlightened understanding of the optoelectronic performance and stability of MAPbI<sub>3</sub> and FAPbI<sub>3</sub> perovskites, which is critically important to guide future research and development of solar devices that are both more efficient and sustainable.
基金supported by King Saud University,Riyadh,Saudi Arabia,under project number RSP2024R397CONAHCYT for the scholarship awarded.
文摘Using the spray pyrolysis process,the work shows the production of pristine and 6%Ag-doped methylammonium lead iodide bromide(MAPbI2Br)film.Through X-ray diffraction analysis,it was found that Ag doping led to a significant increase in grain size to 29.64 nm,alongside reductions in dislocation line density to 5.39×1014 m−2 and d-spacing to 3.18Å,while maintaining the native cubic crystal structure of MAPbI2Br.This research demonstrates a reduction in deep-level trap states with Ag doping,along with a significant narrowing of the band gap to 1.91 eV in the 6%Ag-doped MAPbI2Br.Moreover,the refractive index and extinction coefficient increased to 2.54 and 2.13,respectively.Regarding solar cell performance,all cells demonstrated encouraging outcomes;still,the 6%Ag-doped cell distinguished itself with a fill factor of 0.82,an open-circuit voltage of 1.07 V,an outstanding short-circuit current density of 11.31 mA/cm²,and an efficiency of 10.03%.These results highlight the effectiveness of Ag doping in improving perovskite solar cell technology,marking a notable progress in this field.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12175131 and 11905133)the China Postdoctoral Science Foundation(Grant No.2021M692021)。
文摘Time-of-flight(ToF)transient current method is an important technique to study the transport characteristics of semiconductors.Here,both the direct current(DC)and pulsed bias ToF transient current method are employed to investigate the transport properties and electric field distribution inside the MAPbI_(3) single crystal detector.Owing to the almost homogeneous electric field built inside the detector during pulsed bias ToF measurement,the free hole mobility can be directly calculated to be about 22 cm^(2)·V^(-1)·s^(-1),and the hole lifetime is around 6.5μs–17.5μs.Hence,the mobility-lifetime product can be derived to be 1.4×10^(-4)cm^(2)·V^(-1)–3.9×10^(-4)cm^(2)·V^(-1).The transit time measured under the DC bias deviates with increasing voltage compared with that under the pulsed bias,which arises mainly from the inhomogeneous electric field distribution inside the perovskite.The positive space charge density can then be deduced to increase from 3.1×10^(10)cm^(-3)to 6.89×10^(10)cm^(-3)in a bias range of 50 V–150 V.The ToF measurement can provide us with a facile way to accurately measure the transport properties of the perovskite single crystals,and is also helpful in obtaining a rough picture of the internal electric field distribution.
文摘Using the spray pyrolysis process,the work shows the production of pristine and 6%Ag-doped methylammonium lead iodide bromide(MAPbI2Br)film.Through X-ray diffraction analysis,it was found that Ag doping led to a significant increase in grain size to 29.64 nm,alongside reductions in dislocation line density to 5.39×1014 m−2 and d-spacing to 3.18Å,while maintaining the native cubic crystal structure of MAPbI2Br.This research demonstrates a reduction in deep-level trap states with Ag doping,along with a significant narrowing of the band gap to 1.91 eV in the 6%Ag-doped MAPbI2Br.Moreover,the refractive index and extinction coefficient increased to 2.54 and 2.13,respectively.Regarding solar cell performance,all cells demonstrated encouraging outcomes;still,the 6%Ag-doped cell distinguished itself with a fill factor of 0.82,an open-circuit voltage of 1.07 V,an outstanding short-circuit current density of 11.31 mA/cm²,and an efficiency of 10.03%.These results highlight the effectiveness of Ag doping in improving perovskite solar cell technology,marking a notable progress in this field.
基金supported by National Key Research and Development Program of China(2022YFA1604403)National Natural Science Foundation of China(12274157,12021004,12274334,11904271)Natural Science Foundation of Hubei Province(2023AFA076).Special thanks are given to the Analytical and Testing Center of HUST,the Center of Micro−Fabrication and Characterization(CMFC)of WNLO and LBTEK for the use of their facilities.
文摘The strong coupling between photons and phonons in polar materials gives rise to phonon-polaritons that encapsulate a wealth of physical information,offering crucial tools for the ultrafast terahertz sources and the topological engineering of terahertz light.However,it is still quite challenging to form and manipulate the terahertz phonon-polaritons under the ultrastrong coupling regime till now.In this work,we demonstrate the ultrastrong coupling between the phonon(at 0.95 THz)in a MAPbI3 film and the metallic bound states in the continuum(BICs)in Au metasurfaces.The Rabi splitting can be continuously tuned from 28%to 48.4%of the phonon frequency by adjusting the parameters(size,shape and period)of Au metasurfaces,reaching the ultrastrong coupling regime.By introducing wavelet transform,the mode evolution information of the terahertz phonon-polariton is successfully extracted.It indicates that the phonon radiation intensity of the MAPbI_(3)film is enhanced as the coupling strength is increased.This work not only establishes a new platform for terahertz devices but also opens new avenues for exploring the intricate dynamics of terahertz phonon-polaritons.
基金financial support from the National Natural Science Foundation of China(No.52103223)the Natural Science Basic Research Program of Shaanxi(No.2023-JC-YB-413)+2 种基金the Natural Science Foundation of Heilongjiang Province of China(No.YQ2023E027)the Key Laboratory of Functional Molecular Solids,Ministry of Education(No.FMS20230010)the Fundamental Research Funds for the Central Universities(Nos.3072024GH2605,3072024XX2613,and 3072024XX2616).
文摘Organic–inorganic hybrid perovskites are quite promising candidates in the field of electromagnetic wave (EMW) absorption due to their unique physicochemical properties. However, it is still a considerable challenge to satisfy the light weight, broad bandwidth, and strong absorption properties simultaneously. Herein, the solution of methylammonium lead iodide (MAPbI3) perovskites was infiltrated into the pores of reduced graphene oxide (rGO) aerogels. After drying, a series of MAPbI3/rGO composite aerogel (MGA) materials were synthesized by anchoring the MAPbI3 perovskite nanoparticles to rGO sheets with the assistance of rGO templates. Through the adjustment of component ratios, excellent EMW absorption properties are obtained with the synergistic effects of polarization loss, conduction loss, and multiple reflection and scattering of MAPbI3 and rGO. The porous structure of the aerogel and the suitable group distribution ratio allowed the MGA-4 samples to obtain excellent impedance matching and ultra-low density of ∼ 7.69 mg·cm−3. At a low filling ratio of 15 wt.%, the MGA-4 sample simultaneously achieves highly efficient and broadband EMW absorption performance at a thin thickness. The MGA-4 sample obtained a minimum reflection loss value of −64.35 dB and the effective absorption bandwidth (EAB) value of 5.4 GHz at a thickness of 2.08 mm and a maximum EAB (EABmax) value of 6.2 GHz under 2.22 mm. The MGA-5 sample obtained a maximum EAB value of 6.4 GHz with the thinckness of 2.16 mm. Furthermore, the simulation results of the radar cross-section (RCS) verified the component-optimized composites are capable of achieving excellent EMW attenuation. This paper provides a new approach and valuable reference for the development of hybrid perovskite-based microwave absorption materials with lightweight, ultra-broadband, and strong absorption properties.
