反转型InAs/GaSbⅡ类超晶格太赫兹探测材料及其器件研究

For the inverted type II InAs/GaSb superlattice (SL) structure, the hole state is even higher than the electron state. It has many novel quantum properties and has been proposed for some potential applications like quantum computation. In this application, we will develop the terahertz photodetectors using the hybridization gap of the inverted InAs/GaSb SLs which is at the terahertz wavelength. By combining theoretical calculation with experiments, we aim to investigate the detector design, the growth by molecular beam epitaxy, the optical and electronic transport properties of the inverted SL structure. The focus is on the absorption, photocurrent, the dark current and the noise behavior of the inverted InAs/GaSb type II SL photodetectors. We will reveal the physical mechanism of the electron transition in the inverted band structures and the dominant mechanism of the dark current and the noise behavior. We will also study how to handle the key problems like the low quantum efficiency and the large strain due to the long periodicity of the structure. Finally, based on the inverted type Ⅱ SLs, a prototype photodetector device working in the terahertz range will be achieved. This will provide theoretical and technical support for the development of InAs/GaSb terahertz detectors. The developed InAs/GaSb SLs terahertz detectors will have broad application prospects in military and civil areas such as target detection, secret communication, weapon precision guidance and security check.

反转型(inverted)InAs/GaSbⅡ类超晶格结构的电子能级比空穴能级还低，具有很多新奇的量子特性，在量子计算等方面具有潜在应用。本课题拟利用反转型InAs/GaSbⅡ类超晶格的杂化带隙在太赫兹波段这一特性，制作太赫兹光电探测器。拟采用理论与实验结合的方法，重点研究反转型InAs/GaSbⅡ类超晶格太赫兹探测器的结构设计，材料生长，超晶格光学、电子输运等特性以及器件的光吸收、光电流、暗电流、噪声等物理特性；理解反转能级的电子跃迁机制；研究器件暗电流与噪声的主导机制；解决长周期InAs/GaSb在太赫兹波段吸收小及应变大等关键问题。研制出新型反转型InAs/GaSb超晶格太赫兹探测器原型器件，为InAs/GaSb太赫兹探测器的研制提供理论与技术支持。该探测器将在目标探测、保密通信、武器精确制导和安检等军事和民事领域具有广阔的应用前景。

中文摘要 (对项目的背景、主要研究内容、重要结果、关键数据及其科学意义等做简单概述，800字以内，含标点符号)：.太赫兹探测器在目标探测、保密通信、武器精确制导和安检等军事和民事领域具有广阔的应用前景。本项目针对InAs/GaSb超晶格向太赫兹波段拓展所面临长周期InAs/GaSb在太赫兹波段吸收小及应变大等关键问题，深入开展反转型InAs/GaSb超晶格太赫兹探测器材料结构设计、材料生长、器件制备等方面的研究。取得一下重要结果:.1..开展反转型InAs/GaSb超晶格太赫兹探测器的器件特性研究.基于薛定谔方程和包络函数方法的理论，使用传输矩阵算法（TMM）和8K٠P算法对反转型InAs/GaSb超晶格进行理论设计，优化设计出的反转型InAs/GaSb超晶格结构，优化了反转型InAs/GaSb超晶格生长条件，制备出了高质量反转型InAs/GaSb超晶格材料, XRD结果表明，平均应变为1e-3，超晶格衍射零级峰半宽为44弧秒,达到了项目要求。探索了新型反转型InAs/GaSb超晶格太赫兹探测器单管工艺，制作出新型反转型InAs/GaSb超晶格太赫兹探测器单管，实现70K温度下，光响应波长的100%截止为35微米在太赫兹波段,全面完成项目任务。为InAs/GaSb太赫兹探测器的研制提供理论与技术支持。.2. 研制出中波和长波InAs/GaSb二类超晶格共振隧穿二极管红外光电探测器。中波器件80 K温度下50%探测截止波长为4.8微米，4.9 V时，一个吸收的红外光子产生1.01×105个电子；长波器件在77K下，该RTD光电探测器的最大响应波长为50%截止波长为9.6μm。当施加偏压为1.45V时，测得器件在波长为7.5μm的外量子效率为147%。.3. 研制出中短波双色InAs/GaSb二类超晶格异质结光电晶体管(HPT).短波，器件偏压在1.2V时，光响应率为213 A/W，放大倍数为611。中波器件，偏压在1.3V时，光响应率为45.2 A/W，放大倍数为377。.4. 发现InAs/GaSb二类超晶格多光子吸收效应.设计并制作了二类超晶格红外探测器器件，观察到了2光子、5光子及11光子吸收，为多光子吸收器件的潜在应用开辟了道路。