The Research On The Performance Of Piezo-phototronic Devices Based On The Third-generation Semiconductor(ZnO And SiC)

In the post-Moore era,the development of Io T applications has entered a fast lane with the maturity of 5G technology,proposing higher requirements for various sensors to support the entire Io T system.How to realize the portability,functional diversity and performance optimization of the devices in the sensor network is the concern of industry and academia,and the direct interaction between electronic devices and the human body or the environment is one of the future goals.The piezoelectric effect and piezo-phototronic effect proposed by Academician Wang Zhong Lin proposing provide an effective way for it.They can not only directly convert external mechanical stimulation signals into electrical signals,but also be used to manipulate the performance of electronic and optoelectronic devices.In future electronic systems,they are expected to act as "signal translators" enabling the direct interaction of biomechanical signals with siliconbased electronic devices.Due to the unique properties of the third-generation semiconductor materials,they have great advantages and application prospects in the construction of new multifunctional piezo-phototronic devices.So far,the research and application exploration based on the piezo-phototronic effects of the third-generation semiconductors has achieved fruitful results,both in the construction of new devices and mechanism exploration mostly focused on Zn O and Ga N.In the previous studies of piezo-phototronic effect on the performance modulation of the Si/Zn O heterojunctions,the majority is based on rigid silicon substrate and Zn O one-dimensional nanostructure,which may cause incompatibility with advanced semiconductor processing technology,as well as the limitation of its application in the field of wearable applications.Meanwhile,the restriction on the direction of the single compression strain also hinders further exploration of the regulatory mechanism of the heterojunction interface properties.In addition,as a typical thirdgeneration semiconductor material,the research and application of 4H-Si C in the field of piezo-phototronic are still blank.Therefore,it is necessary to further expand the application and mechanism exploration of the piezoelectric materials in third-generation semiconductors.In this thesis,the flexible Si/Zn O film heterojunction optoelectronic devices are fabricated by means of flexible silicon wafers and the regulation mechanism of piezo-phototronic effects under different strain(directions,size)is systematically explored.Secondly,the 4H-Si C nanowire arrays were prepared by electrochemical etching method,and the 4H-Si C nanowire arrays Schottky junction is constructed to explore the influence of the piezotronics and piezophototronic effect on its electrical transport and optoelectronic properties.The main research contents are as follows:(1)In Chapter 3,flexible p-Si/n-Zn O film heterojunction photodetectors have been constructed by depositing Zn O films on chemically thinned Si substrates by magnetron sputtering.Under 405 nm light illumination and at-0.5 V bias,the reverse photocurrent of the heterojunction under the-0.73‰ compression strain increased by 50.36% compared to that under a strain-free state,while the reverse photocurrent of the heterojunction under 0.73‰ tensile strain decreased by 29.2% compared to that under the strain-free state.The introduction of flexible silicon wafer realizes the controllable regulation of bidirectional photocurrent response,which lies in the fact that the strain-induced piezo-potential governs the local energy band structure at the heterojunction interfaces and thus influences the carrier transport behavior in the heterojunction region.The COMSOL simulation results further verify the evolution of the energy band structure at the heterojunction interface under different strain states.This work provides a unique strategy to design flexible silicon-based optoelectronic devices via the piezo-phototronic effect of the Zn O film.(2)In Chapter 4,we attempt to explore the piezo-phototronic effect of 4H-Si C in third-generation semiconductors.In this work,the 4H-Si C nanowire arrays were prepared by electrochemical etching method and formed Schottky contacts with gold electrodes.The research results show that the dark current of the Au/4H-Si C Schottky junction increases from 0.699 μA to 1.682 μA,and the photocurrent increases from28.17 μA to 33.98 μA under the compressive strain.This work realized the piezotronics effect and piezophototronic effect of 4H-Si C material for the first time.It lays a foundation for the subsequent systematic research on 4H-Si C-based piezotronics and piezo-photoctronic devices...