基于压电光电子学效应的高性能整流接触MoS2光探测器研制

Piezo-phototronic effect is a three way coupling effect of piezoelectric, semiconductor and photonic properties in non-central symmetric semiconductor materials, using the piezoelectric potential that is generated by applying a strain to a semiconductor with piezoelectricity to control the carrier generation, transport, separation and/or recombination at metal-semiconductor junction or p-n junction for improving the performance of optoelectronic devices. And it has been widely used in micro nano mechatronics system and human-computer interaction. The two-dimensional layered materials, such MoS2, possess a unique the atomic thickness, and has a strong gate coupling effect. Combined with its excellent photoelectric performance, it is beneficial to fabricate high-performance photodetectors with low dark current and high photoresponsivity. The heterogeneous integration of traditional piezoelectric materials with MoS2, based on piezo-phototronic effect, can achieve the regulation performance of MoS2 photodetector and obtain quantitative modulation limits, which is of great significance for the development of high-performance photodetectors. This project aim to the contact interface challenges of MoS2 piezo-phototronic devices, and the Van der Waals contact interface between GaN and MoS2 can be obtained with physical transfer method. Thus, low interface defects and rectifying contact can be obtained, This project proposes the way for combining the special properties of MoS2 and GaN in terms of semiconductor characteristics and photo excitation and piezoelectric effect, which can achieve the purpose of synergy of mechano-optical-electro coupling effect. Based on the physical devices with ultimate performance of MoS2 photodetectors, it is of practical significance to expand the application field of piezoelectric optical electronic devices.

压电效应、光激发和半导体传输特性三相耦合的压电光电子学效应可以利用应变引起的压电势来调节和控制光电过程，在微纳机电系统和人机交互等领域得到广泛应用。以MoS2为代表的二维层状材料具有原子层级别的厚度，利于实现较强的栅极耦合效果。结合其优异的光电性能，有利于低暗电流、高光响应度的光探测研制。将其与传统压电材料进行异质集成，基于压电光电子学效应实现对MoS2光探测器性能的调控，获取定量调控极限，对于研制高性能光探测器具有重要意义。本项目以MoS2压电光电子学场效应晶体管的接触界面控制为出发点，利用物理转移法获得GaN与MoS2的范德华异质接触界面，减少界面缺陷并实现整流接触。充分发挥MoS2和GaN的半导体、光激发和压电特性，达到力-光-电耦合协同作用的目的，构建基于压电光电子学效应的高性能MoS2光探测器。从物理器件出发，获取MoS2光探测器的极限性能，拓展压电光电子学器件的应用。

现代晶体管主要继续沿着更快、更小、成本更加低廉的方向发展。不断地缩小晶体管特征尺寸，提升了晶体管的开关速度和截止频率。以MoS2为代表的二维层状材料具有原子层级别的厚度，利于实现较强的栅极耦合效果。结合其优异的光电性能，有利于低暗电流、高光响应度的光探测研制。将其与传统材料进行异质集成，实现对MoS2光探测器性能的调控，获取定量调控极限，对于研制高性能光探测器具有重要意义。本项目深入研究了二维半导体与其它功能材料之间的异质集成，着重于深入理解界面态对二维电子材料器件性能的影响机制，并实现有效调控。阐明沟道材料厚度、介电层厚度、电极接触、异质界面质量等因素对叠层器件的可靠性和稳定性的影响规律。针对二维半导体器件的介质层结构设计开了探索性工作，实现了低界面态异质结构界面；在优化栅极异质界面的基础上，通过对栅极材料和结构进行合理设计获得了大电流、超陡峭场效应晶体管。同时，探索了相关高性能低功耗器件在光电探测方面的应用，获得了宽光谱高响应度的快速光探测器件。