Theoretical Simulation And Experimental Verification Of The Statistical Piezotronic Effect Of Interfacial Double Schottky Barriers

After Prof.Zhong Lin Wang founded the piezotronic effect,this field has developed rapidly,attracting a large number of domestic and foreign research teams to devote to the research of piezoelectric electronics theory and devices.However,previous research on the piezotronic effect has focused on devices or systems with only one or a limited number of interfaces.Due to the random orientation,the piezotronic effect can only play a very limited role in a system consisting of millions of piezoelectric cells with countless interfaces.Until now,the application of compressive stress to bulk materials containing millions of interfaces has not been reported to have reduced or constant conductivity.Therefore,it is very important to explore the regulation mechanism of the piezotronic effect with a large number of interfaces.The purpose of this study is to reveal the possibility of statistical adjustment mechanisms for the piezotronic effect of numerous interfaces in bulk materials.Firstly,we prepared a large number of single and double pieces of zinc oxide by low temperature hydrothermal method,and found it belongs to the single crystal material with good crystallinity and wurtzite structure by characterization.Then,we studied the stress-current transmission characteristics of ZnO single crystal nanoparticle and sintered block samples with random statistical orientation distribution of internal single crystal.It is found that the random orientation distribution of a large number of piezoelectronic interfaces leads to the optimization of the current channel so that the current transmission ability of the system can be improved as the stress increases,which is in line with our definition of the statistical piezotronic effect,and this is its first regulatory action.Then,we verified the feasibility of using EDA(Electronic Design Automation)circuit model instead of FEA(Finite Element Analysis)for theoretical calculation.Through the simulation of three-dimensional equivalent circuit,it is found that the circuit simulation output of ZnO array system with random oriented single crystal is consistent with the research result of ZnO single crystal nanoparticle pressed block sample,which verifies the first regulation behavior of the statistical piezotronic effect in theory.The equivalent circuit output of ZnO array system with uniform orientation of inner single crystal leads to the output current decreases with increasing stress.We analyzed that this phenomenon belongs to the regulation category of the statistical piezotronic effect,and this is the second regulatory behavior of the statistical piezotronic effect,which is the calculated result from the perspective of theoretical simulation.Finally,by studying the ZnO single-sheet tableting system and the dual-sheet tableting system,we experimentally verified the calculated second regulation behavior of the statistical piezotronic effect.It also elaborates that the sintering process may damage the internal structure of the tablet device and make the device that originally had the second regulation mechanism of the statistical piezotronic effect invalid.In summary,we proposed the statistical piezotronic effect,and proved the existence and effectiveness of the statistical piezotronic effect from the perspective of theoretical calculation and experimental verification.