Coupling TiO2 with a narrow band gap semiconductor acting as the photosensitizer has attracted much attention in solar energy exploitation.In this work,the porous TiO2 film was first formed on the conducting glass pla...Coupling TiO2 with a narrow band gap semiconductor acting as the photosensitizer has attracted much attention in solar energy exploitation.In this work,the porous TiO2 film was first formed on the conducting glass plate(CGP)substrate by the decomposition of polyethylene glycol(PEG)mixing in titanium hydroxide sol at 450℃.Then,the TiO2/Ag2Se interface composite film was fabricated by interface reaction of AgNO3 with NaSeSO3 on the activated surface of porous TiO2 film.The results of SEM and XRD analyses indicated that the porous TiO2 layer was made up of the anatase crystal,and the Ag2Se layer was made up of congregative small particles that have low-temperatureα-phase structure.Due to its efficient charge separation for the photo-induced electron-hole pairs,the TiO2/Ag2Se interface composite film as-prepared has good photovoltaic property and high photocurrent response for visible light,which have been confirmed by the photoelectrochemical measurements.展开更多
Compositing a secondary phase in Ag_(2)Se can usually tune the electron and phonon scattering to improve the thermoelectric performance.However,the intrinsically high carrier concentration still limits the performance...Compositing a secondary phase in Ag_(2)Se can usually tune the electron and phonon scattering to improve the thermoelectric performance.However,the intrinsically high carrier concentration still limits the performance optimization.Here,we employ a modulation decoration strategy to simultaneously achieve submicron-scale constituents and compositional modification for synergistic optimization of thermoelectric properties.Amorphous nano Sb_(2)S_(3) has been decorated on the surface of Ag_(2)Se powders,and S was added into the Ag_(2)Se matrix through an ion exchange reaction accompanied by the formation of a crystal/amorphous mixed secondary phase of Sb_(2)(S,Se)_(3).The S doping reduced the excessive intrinsic carrier concentration,leading to modified electrical transport properties and significantly reduced electrical thermal conductivity.On the other hand,introducing the S dopants and the crystal/amorphous interfaces into the Ag_(2)Se matrix could increase the lattice anharmonicity,further contributing to the reduced thermal conductivity.Consequently,the Ag_(2)Se-0.4%Sb_(2)S_(3) sample obtains a high average zT value of>1 in the temperature range of 300–390 K.In addition,the maximum cooling temperature difference of over 85 K can be predicted in an Ag_(2)Se/Ag_(2)Se-0.4%Sb_(2)S_(3) segregated module at the hot side temperature of 350 K.展开更多
In this work,Ag/Ag_(2)Se composite films with excellent thermoelectric(TE)properties and flexibility are prepared based on a simple one-pot method.By adjusting the nominal ratios of Ag/Se,an optimal Ag/Ag_(2)Se compos...In this work,Ag/Ag_(2)Se composite films with excellent thermoelectric(TE)properties and flexibility are prepared based on a simple one-pot method.By adjusting the nominal ratios of Ag/Se,an optimal Ag/Ag_(2)Se composite film shows a large power factor of~2275 μW m^(-1) K^(-2) at 300 K.Such an outstand-ing TE performance of the composite film is due to the unique microstructure and the synergistic effect between the Ag and Ag_(2)Se.Meanwhile,the composite film also shows outstanding flexibility(~91.8%of the initial electrical conductivity is maintained,and the S is unchanged after 1500 bending cycles with a bending radius of 4 mm).Furthermore,a 4-leg flexible TE generator assembled with the optimal film produces a voltage of 14.06 mV and 4.96 μW at a temperature difference of 30.4 K.This work provides a new inspiration for the preparation of flexible Ag_(2)Se-based films with excellent TE performance near room temperature.展开更多
Diffusion barrier materials(DBMs)are critical for the stability and efficiency of thermoelectric devices.Conventional DBM selection via density functional theory(DFT)calculations is computationally intensive.Here,we i...Diffusion barrier materials(DBMs)are critical for the stability and efficiency of thermoelectric devices.Conventional DBM selection via density functional theory(DFT)calculations is computationally intensive.Here,we introduce an efficient screening approach that employs substitution energy as a surrogate for interfacial reaction energy,significantly reducing computational demand.By integrating substitution energy with migration energy barriers,we identify Ni as a robust DBM for Ag_(2)Se.Experimental validation confirms that Ni/Ag_(2)Se joints exhibit low contact resistivity(6.6μΩ·cm^(2))and high thermal stability after 30 days of thermal aging.The Te-free Ag_(2)Se/MgAgSb devices achieve a maximum cooling temperature difference of 68 K at 350 K,comparable to state-of-the-art Ag_(2)Se/Bi_(2)Te_(3) devices,while demonstrating excellent durability over 2000 power cycles.This strategy offers a rapid and reliable framework for DBM selection,accelerating the advancement of high-performance thermoelectric devices.展开更多
Flexible thermoelectric power generation isincreasingly recognized as a viable solution for poweringwearable electronic devices. However, the performance limitationsof n-type flexible thin films have restricted their ...Flexible thermoelectric power generation isincreasingly recognized as a viable solution for poweringwearable electronic devices. However, the performance limitationsof n-type flexible thin films have restricted their widerapplication. Here, we successfully fabricated n-type Ag_(2)Se thinfilms with a high power factor of 2.14 mW m^(−1) K^(−2) at 300 Kthrough texture engineering. Utilizing a straightforwardthermal evaporation technique, we produced (201)-textured ntypeAg_(2)Se thin films by employing Se precursor strategies.Both experimental and theoretical analyses reveal that Ag_(2)Sethin films with this specific orientation exhibit superior carriermobility and a high Seebeck coefficient. Moreover, theinherent low thermal conductivity of Ag_(2)Se is further reducedby the presence of nanopores and random in-plane orientation,which effectively scatter phonons across various wavelengths.As a result, the Ag_(2)Se films achieved an optimal ZTvalue of 0.73 at 363 K, suggesting substantial potential forfurther improvements. This research not only demonstrates astrategic method to manipulate the crystallographic orientationof Ag_(2)Se thin films but also opens up new possibilities fordeveloping high-performance thermoelectric materials.展开更多
基金Supported by the National Natural Science Foundation of China(Grant Nos.20875001,20775001,50532030&20771001)Innovation Foundation of Anhui Province(Grant No.2006KJ007TD)
文摘Coupling TiO2 with a narrow band gap semiconductor acting as the photosensitizer has attracted much attention in solar energy exploitation.In this work,the porous TiO2 film was first formed on the conducting glass plate(CGP)substrate by the decomposition of polyethylene glycol(PEG)mixing in titanium hydroxide sol at 450℃.Then,the TiO2/Ag2Se interface composite film was fabricated by interface reaction of AgNO3 with NaSeSO3 on the activated surface of porous TiO2 film.The results of SEM and XRD analyses indicated that the porous TiO2 layer was made up of the anatase crystal,and the Ag2Se layer was made up of congregative small particles that have low-temperatureα-phase structure.Due to its efficient charge separation for the photo-induced electron-hole pairs,the TiO2/Ag2Se interface composite film as-prepared has good photovoltaic property and high photocurrent response for visible light,which have been confirmed by the photoelectrochemical measurements.
基金financially supported by the National Natural Science Foundation of China(Nos.52472105,52272246,and 12074015)the Sichuan Science and Technology Program(Nos.2024YFHZ0309 and 2023NSFSC1596)the State Key Laboratory for Mechanical Behavior of Materials(No.20232509).
文摘Compositing a secondary phase in Ag_(2)Se can usually tune the electron and phonon scattering to improve the thermoelectric performance.However,the intrinsically high carrier concentration still limits the performance optimization.Here,we employ a modulation decoration strategy to simultaneously achieve submicron-scale constituents and compositional modification for synergistic optimization of thermoelectric properties.Amorphous nano Sb_(2)S_(3) has been decorated on the surface of Ag_(2)Se powders,and S was added into the Ag_(2)Se matrix through an ion exchange reaction accompanied by the formation of a crystal/amorphous mixed secondary phase of Sb_(2)(S,Se)_(3).The S doping reduced the excessive intrinsic carrier concentration,leading to modified electrical transport properties and significantly reduced electrical thermal conductivity.On the other hand,introducing the S dopants and the crystal/amorphous interfaces into the Ag_(2)Se matrix could increase the lattice anharmonicity,further contributing to the reduced thermal conductivity.Consequently,the Ag_(2)Se-0.4%Sb_(2)S_(3) sample obtains a high average zT value of>1 in the temperature range of 300–390 K.In addition,the maximum cooling temperature difference of over 85 K can be predicted in an Ag_(2)Se/Ag_(2)Se-0.4%Sb_(2)S_(3) segregated module at the hot side temperature of 350 K.
基金National Natural Science Foundation of China (Nos. 92163118 and 51972234).
文摘In this work,Ag/Ag_(2)Se composite films with excellent thermoelectric(TE)properties and flexibility are prepared based on a simple one-pot method.By adjusting the nominal ratios of Ag/Se,an optimal Ag/Ag_(2)Se composite film shows a large power factor of~2275 μW m^(-1) K^(-2) at 300 K.Such an outstand-ing TE performance of the composite film is due to the unique microstructure and the synergistic effect between the Ag and Ag_(2)Se.Meanwhile,the composite film also shows outstanding flexibility(~91.8%of the initial electrical conductivity is maintained,and the S is unchanged after 1500 bending cycles with a bending radius of 4 mm).Furthermore,a 4-leg flexible TE generator assembled with the optimal film produces a voltage of 14.06 mV and 4.96 μW at a temperature difference of 30.4 K.This work provides a new inspiration for the preparation of flexible Ag_(2)Se-based films with excellent TE performance near room temperature.
基金supported by the National Natural Science Foundation of China(Nos.U21A2054,51961011,and 52273285)financial support from the Australian Research Council,HBIS Group-University of Queensland(HBIS-UQ)Innovation Centre for Sustainable Steel project'the Queensland University of Technology(QUT)Capacity Building Professor Program.
文摘Diffusion barrier materials(DBMs)are critical for the stability and efficiency of thermoelectric devices.Conventional DBM selection via density functional theory(DFT)calculations is computationally intensive.Here,we introduce an efficient screening approach that employs substitution energy as a surrogate for interfacial reaction energy,significantly reducing computational demand.By integrating substitution energy with migration energy barriers,we identify Ni as a robust DBM for Ag_(2)Se.Experimental validation confirms that Ni/Ag_(2)Se joints exhibit low contact resistivity(6.6μΩ·cm^(2))and high thermal stability after 30 days of thermal aging.The Te-free Ag_(2)Se/MgAgSb devices achieve a maximum cooling temperature difference of 68 K at 350 K,comparable to state-of-the-art Ag_(2)Se/Bi_(2)Te_(3) devices,while demonstrating excellent durability over 2000 power cycles.This strategy offers a rapid and reliable framework for DBM selection,accelerating the advancement of high-performance thermoelectric devices.
基金supported by the National Key Research and Development Program of China (2023YFB3809400)the National Natural Science Foundation of China (52130203 and 92463310)。
文摘Flexible thermoelectric power generation isincreasingly recognized as a viable solution for poweringwearable electronic devices. However, the performance limitationsof n-type flexible thin films have restricted their widerapplication. Here, we successfully fabricated n-type Ag_(2)Se thinfilms with a high power factor of 2.14 mW m^(−1) K^(−2) at 300 Kthrough texture engineering. Utilizing a straightforwardthermal evaporation technique, we produced (201)-textured ntypeAg_(2)Se thin films by employing Se precursor strategies.Both experimental and theoretical analyses reveal that Ag_(2)Sethin films with this specific orientation exhibit superior carriermobility and a high Seebeck coefficient. Moreover, theinherent low thermal conductivity of Ag_(2)Se is further reducedby the presence of nanopores and random in-plane orientation,which effectively scatter phonons across various wavelengths.As a result, the Ag_(2)Se films achieved an optimal ZTvalue of 0.73 at 363 K, suggesting substantial potential forfurther improvements. This research not only demonstrates astrategic method to manipulate the crystallographic orientationof Ag_(2)Se thin films but also opens up new possibilities fordeveloping high-performance thermoelectric materials.
