Flexoelectricity refers to the mechanical-electro coupling between strain gradient and electric polarization, and conversely, the electro-mechanical coupling between electric field gradient and mechanical stress. This...Flexoelectricity refers to the mechanical-electro coupling between strain gradient and electric polarization, and conversely, the electro-mechanical coupling between electric field gradient and mechanical stress. This unique effect shows a promising size effect which is usually large as the material dimension is shrunk down. Moreover, it could break the limitation of centrosymmetry, and has been found in numerous kinds of materials which cover insulators, liquid crystals, biological materials, and semiconductors. In this review, we will give a brief report about the recent discoveries in flexoelectricity, focusing on the flexoelectric materials and their applications. The theoretical developments in this field are also addressed. In the end, the perspective of flexoelectricity and some open questions which still remain unsolved are commented upon.展开更多
The resistive switching(RS)mechanism of hybrid organic–inorganic perovskites has not been clearly understood until now.A switchable diode-like RS behavior in MAPbBr3 single crystals using Au(or Pt)symmetric electrode...The resistive switching(RS)mechanism of hybrid organic–inorganic perovskites has not been clearly understood until now.A switchable diode-like RS behavior in MAPbBr3 single crystals using Au(or Pt)symmetric electrodes is reported.Both the high resistance state(HRS)and low resistance state(LRS)are electrode-area dependent and light responsive.We propose an electric-fielddriven inner p–n junction accompanied by a trap-controlled space-charge-limited conduction(SCLC)conduction mechanism to explain this switchable diode-like RS behavior in MAPbBr_(3) single crystals.展开更多
Hybrid perovskite solar cells(PSCs)have been intensively studied in recent years because of their high efficiency and low costs.For PSCs,the electron transport layer(ETL)is a key for its photoelectric conversion effic...Hybrid perovskite solar cells(PSCs)have been intensively studied in recent years because of their high efficiency and low costs.For PSCs,the electron transport layer(ETL)is a key for its photoelectric conversion efficiency.Here we demonstrate the application of amorphous InGaZnO_(4)thin films as ETL for efficient PSCs by pulsed laser deposition(PLD).The PSC device using such InGaZnO_(4)amorphous film as ETL has achieved an efficiency of 15.1%.The outstanding performance is attributed to the excellent properties of amorphous InGaZnO_(4)oxide thin films,including high electron mobility and high transparency,what is more,the electronic properties of the films can be controlled by changing the partial pressure of oxygen in the deposition chamber and post-deposition annealing process.Our result will be helpful for preparation of large area PSCs and other opto-electric devices at low temperature by physical vapor deposition method.展开更多
基金supported by the National Natural Science Foundation of China under Grant Nos. 11574126 and 11604135the Natural Science Foundation of Jiangxi Province (No. 20161BAB216110)+1 种基金China Postdoctoral Science Foundation (No. 2017M612162)Postdoctoral Science Foundation of Jiangxi Province (No. 2017KY02)
文摘Flexoelectricity refers to the mechanical-electro coupling between strain gradient and electric polarization, and conversely, the electro-mechanical coupling between electric field gradient and mechanical stress. This unique effect shows a promising size effect which is usually large as the material dimension is shrunk down. Moreover, it could break the limitation of centrosymmetry, and has been found in numerous kinds of materials which cover insulators, liquid crystals, biological materials, and semiconductors. In this review, we will give a brief report about the recent discoveries in flexoelectricity, focusing on the flexoelectric materials and their applications. The theoretical developments in this field are also addressed. In the end, the perspective of flexoelectricity and some open questions which still remain unsolved are commented upon.
基金supported by the National Natural Science Foundation of China(Nos.11964017,51972157,11864022,and 51662028)the Natural Science Foundation of Jiangxi Province(No.20192ACB21017)。
文摘The resistive switching(RS)mechanism of hybrid organic–inorganic perovskites has not been clearly understood until now.A switchable diode-like RS behavior in MAPbBr3 single crystals using Au(or Pt)symmetric electrodes is reported.Both the high resistance state(HRS)and low resistance state(LRS)are electrode-area dependent and light responsive.We propose an electric-fielddriven inner p–n junction accompanied by a trap-controlled space-charge-limited conduction(SCLC)conduction mechanism to explain this switchable diode-like RS behavior in MAPbBr_(3) single crystals.
基金supported by the National Natural Science Foundation of China(Nos.51972157,11964017)the Jiangxi’s Natural Science Foundation(No.20192ACB21017)the financial support from Hubei Key Laboratory of Ferro and Piezoelectric Materials and Devices(No.K201803).
文摘Hybrid perovskite solar cells(PSCs)have been intensively studied in recent years because of their high efficiency and low costs.For PSCs,the electron transport layer(ETL)is a key for its photoelectric conversion efficiency.Here we demonstrate the application of amorphous InGaZnO_(4)thin films as ETL for efficient PSCs by pulsed laser deposition(PLD).The PSC device using such InGaZnO_(4)amorphous film as ETL has achieved an efficiency of 15.1%.The outstanding performance is attributed to the excellent properties of amorphous InGaZnO_(4)oxide thin films,including high electron mobility and high transparency,what is more,the electronic properties of the films can be controlled by changing the partial pressure of oxygen in the deposition chamber and post-deposition annealing process.Our result will be helpful for preparation of large area PSCs and other opto-electric devices at low temperature by physical vapor deposition method.
