摘要
The enhanced electromechanical performance of metal-insulator-semiconductor tunneling diodes(MISTDs)based on ZnO nanostructures is investigated through modeling in the framework of the Schrödinger equation with effective-mass approximation.It is found that the performance of ZnO based diodes is greatly improved by inserting an MgO layer which allows the inhibition of the screening effect.The piezoelectric response of MISTDs is much higher than that of metal-semiconductor-metal Schottky diodes MSMSDs.The current of the MISTDs is almost zero at -2%compressive strain and increases to a much higher value(∼600 nA)than that of the MSMSDs(∼400 nA)at+2%tensile strain.The enhancement mechanism of MISTDs is investigated by examining the electron density,electric field,electrostatic potential and conduction band edge of the device.The results found that the origin of the enhanced electromechanical performance is due to the inhibition of screening effects by the insulating MgO layer which leads to a highly strain sensitive energy barrier in the ZnO layer and an extra energy barrier in the MgO layer with a strain modulated height.
基金
supported by the National Basic Research Program of China(no.2013CB932602)
the Program of Introducing Talents of Discipline to Universities(no.B14003)
National Natural Science Foundation of China(no.51572021,and 51527802)
Beijing Municipal Science&Technology Commission
the Fundamental Research Funds for Central Universities,and the Newton International Research Collaboration Programme(no.NRCP/1415/129).
