Theoretical Study Of Strain Modulation Piezoelectric Semiconductor Devices

Piezoelectric semiconductor material combines semiconductor characteristics and piezoelectric characteristics,making the piezoelectric semiconductor device has a unique property that utilizes the piezoelectric effect of the material due to the application of external stress,which can not only convert mechanical energy into electrical energy,but also convert stress and strain signals into electrical signals,which means that electrical and mechanical coupling can be achieved.Thus,it is possible to design and prepare a series of novel strain sensing and energy conversion devices based on piezoelectric semiconductor materials through force-electric coupling,and in particular,nanostructure piezoelectric semiconductor devices with high performance characteristics.At present,the study of piezoelectric semiconductor nanomaterials and nanodevices coupling piezoelectric and semiconducting properties has become a hot topic in nanotechnology research and a cross cutting frontier.Experimental and theoretical studies have found that piezoelectric nanomaterials,such as wurtzite-structured of zinc oxide and gallium nitride,etc.can be used as novel sensing^[1]and transducing devices^[2],especially for designing high sensitivity and ultra-low power loss sensing and transducing devices,and have a huge potential application especially in flexible electronics^[3],wearable electronics^[4]and wireless sensors^[5]which is multifunctional and low powered.Based on numerous experimental and theoretical researches,a new interdisciplinary subject called piezoelectric has been established.Piezoelectronics is a discipline about how piezoelectric semiconductor materials nanodevices and quantum devices efficiently regulate the internal carrier transport,quantum transport,and other characteristics of the material under external stress,which is caused by strain and thus change the material properties.This is a unique interdisciplinary discipline that applies the force-electric coupling effect on the nanoscale and is unique in technology,and can provide a new platform for nonlinear coupled physics research.The electromechanical coupling effects of piezoelectric electronics combines piezoelectric theory with semiconductor theory,making it potentially significant in many fields such as nanorobots^[6],human-computer interaction systems^[7],light-emitting diodes^[8],photovoltaic cells^[9],and solar cells^[10],which has greatly broadened the traditional piezoelectric materials research and application fields.And a series of new devices,such as nano-generators^[11]nano-piezoelectronics sensors^[12],nano-energy packages^[13],etc.have shown great application prospects.The content of this paper mainly includes:1?Use one-dimensional zinc oxide nanowire piezoelectric semiconductor device as an example to describe piezoelectric electronics theory based on piezoelectric semiconductor PN junction and metal-piezoelectric semiconductor contact,which are suitable for constructing high sensitivity strain-controlled piezoelectric semiconductor sensor devices.2?Based on the theory of piezoelectric electronics,we demonstrated the current-voltage characteristics and frequency characteristics of piezoelectric semiconductor PIN junction.Due to the unique structure of the PIN junction,it has a wide range of applications from low frequency to high frequency,which mainly include applications in radio frequency circuits and high frequency microwave circuits.In this dissertation,the piezoelectric modulation characteristics of piezoelectric semiconductor PIN junctions in photodetectors and light-emitting diodes are studied.Based on this,the piezoelectric semiconductor PIN diode microwave device model is discussed.The change of high-frequency characteristics under piezoelectric control is obtained by analyzing the capacitance and resistance.3?We showed the law of the strain-generating piezoelectric field regulating the tunnel diode of the piezoelectric semiconductor material,namely the piezoelectric modulation characteristic.The tunnel diode is different from the ordinary diode.Its working mechanism is quantum tunneling.We can regulate the tunneling process of the electrons in the piezoelectric tunnel diode by external stress,so that the performance of the piezoelectric tunnel diode in the infrared rectenna antenna is more sensitive.We studied piezoelectric semiconductor devices and found that the piezoelectric charge generated by the strain affects the distribution and movement of carriers in the device.The piezoelectric potential influences the interface energy band bending and the barrier height,so that the electrical and optical properties in piezoelectric semiconductor devices can be controlled by the strain.The significance of this work is to provide a theoretical guide for designing emerging electronic devices with high sensitivity and low power consumption.