Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation en...Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation engineering strategy of PbBr_(2)precursor film to accelerate its reaction with CsBr precursor during two-step sequential deposition of CsPbBr_(3)films.Such a novel strategy is proceeded by adding CsBr species into PbBr_(2)precursor,which can tailor the preferred crystal orientation of PbBr_(2)film from[020]into[031],with CsBr additive staying in the film as CsPb_(2)Br_(5)phase.Theoretical calculations show that the reaction energy barrier of(031)planes of PbBr_(2)with CsBr is lower about 2.28 eV than that of(O2O)planes.Therefore,CsPbBr_(3)films with full coverage,high purity,high crystallinity,micro-sized grains can be obtained at a low temperature of 150℃.Carbon-electrode PSCs with these desired CsPbBr_(3)films yield the record-high efficiency of 10.27%coupled with excellent operation stability.Meanwhile,the 1 cm^(2)area one with the superior efficiency of 8.00%as well as the flexible one with the champion efficiency of 8.27%and excellent mechanical bending characteristics are also achieved.展开更多
This study used density functional theory and the quantum transport method to investigate the interfacial coupling and spin transport of transition metals(TMs)with a Fe,Co,and Ni/2H-VSe_(2)hybrid nanostructure.Because...This study used density functional theory and the quantum transport method to investigate the interfacial coupling and spin transport of transition metals(TMs)with a Fe,Co,and Ni/2H-VSe_(2)hybrid nanostructure.Because the indirect coupling of TM-Se-V led to an obvious reduction of the magnetic moment and the disappearance of the half-metal characteristics of 2H-VSe_(2),the expected spin-filtering effect of individual TMs and 2H-VSe_(2)deteriorated at the contact region.Nevertheless,all the TM/2H-VSe_(2)-based dual-probe devices exhibited an interesting bias-dependent spin-injection efficiency with a maximum output spin-polarized current of 666 mA mm-1 in Co/2H-VSe_(2).The proposed TM/2H-VSe_(2)-based spin-field-effect transistor demonstrated outstanding performance.The Ni/2H-VSe_(2)-based transistor achieved a maximum output spin-polarized current of 3117 m A mm-1 and demonstrated a good switching characteristic of 106 mV dec-1.Importantly,all transistors achieved a widely tunable scale of spin-extraction efficiency ranging consistently between 96%and-92%with gate bias.These results indicate a promising candidate for use in high-performance spintronic devices.展开更多
基金the financial support from the National Key R&D program of China(2021YFF0500501 and 2021YFF0500504)the Fundamental Research Funds for the Central Universities(YJS2213 and JB211408)+1 种基金the National Natural Science Foundation of China(61874083)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(No.2020GXLH-Z-014)
文摘Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation engineering strategy of PbBr_(2)precursor film to accelerate its reaction with CsBr precursor during two-step sequential deposition of CsPbBr_(3)films.Such a novel strategy is proceeded by adding CsBr species into PbBr_(2)precursor,which can tailor the preferred crystal orientation of PbBr_(2)film from[020]into[031],with CsBr additive staying in the film as CsPb_(2)Br_(5)phase.Theoretical calculations show that the reaction energy barrier of(031)planes of PbBr_(2)with CsBr is lower about 2.28 eV than that of(O2O)planes.Therefore,CsPbBr_(3)films with full coverage,high purity,high crystallinity,micro-sized grains can be obtained at a low temperature of 150℃.Carbon-electrode PSCs with these desired CsPbBr_(3)films yield the record-high efficiency of 10.27%coupled with excellent operation stability.Meanwhile,the 1 cm^(2)area one with the superior efficiency of 8.00%as well as the flexible one with the champion efficiency of 8.27%and excellent mechanical bending characteristics are also achieved.
基金the 111 project(B12026)the National Natural Science Foundation of China(61904142)the Natural Science Basic Research Plan in Shaanxi Province of China(2019ZDLGY16-03)。
文摘This study used density functional theory and the quantum transport method to investigate the interfacial coupling and spin transport of transition metals(TMs)with a Fe,Co,and Ni/2H-VSe_(2)hybrid nanostructure.Because the indirect coupling of TM-Se-V led to an obvious reduction of the magnetic moment and the disappearance of the half-metal characteristics of 2H-VSe_(2),the expected spin-filtering effect of individual TMs and 2H-VSe_(2)deteriorated at the contact region.Nevertheless,all the TM/2H-VSe_(2)-based dual-probe devices exhibited an interesting bias-dependent spin-injection efficiency with a maximum output spin-polarized current of 666 mA mm-1 in Co/2H-VSe_(2).The proposed TM/2H-VSe_(2)-based spin-field-effect transistor demonstrated outstanding performance.The Ni/2H-VSe_(2)-based transistor achieved a maximum output spin-polarized current of 3117 m A mm-1 and demonstrated a good switching characteristic of 106 mV dec-1.Importantly,all transistors achieved a widely tunable scale of spin-extraction efficiency ranging consistently between 96%and-92%with gate bias.These results indicate a promising candidate for use in high-performance spintronic devices.