兼容集成中的新型材料系探索与特殊超晶格结构研究年度报告

Annual Report of the Exploration of Novel Material System and Special Superlattice Structures in the Compatible Integration

含边缘元素的III-V族光电子合金材料是近些年逐渐兴起的一种新型材料系,开展相关研究的国家较少,这些合金的基本特性、合成以及器件应用等方面还存在很多未知,亟需推动。为此,该研究在含边缘元素的III-V族光电子材料的理论计算、合成实验与特性表征方面系统地开展基础创新研究。在理论研究方面,我们利用第一性原理重点计算了GaN1-xBix和InP1-xBix三元合金的电子结构与光学特性等,预测了Bi元素并入对合金物理性质的影响。在III-V族含硼材料的合成与特性表征方面,利用低压金属有机化学气相沉积技术,在GaAs上生长出了BGaAsB四元合金与BGaAsSb/GaAs MQW,明确了B并入对于Sb并入以及Ga As Sb/Ga As MQW光致发光特性的影响。基于InAs/GaSb二类超晶格实现短波、甚长波及窄带长波/甚长波双色红外探测器的研究,生长的材料具有极高的材料质量.短波探测器单管器件在77 K条件下50%截止波长为2.56μm,峰值探测率为1.3×1011cm·Hz1/2·W^(-1);中波探测器单管器件在77 K条件下50%截止波长为4.3μm,峰值探测率为2.4×1011 cm·Hz1/2·W^(-1);甚长波红外探测器单管器件在77 K条件下50%截止波长为14.5μm,量子效率为14%,热噪声限制的探测率为4.3×109 cm·Hz1/2 W^(-1).研究了分子束外延生长的中波、长波、甚长波波段的InAs/GaSb二类超晶格吸收层材料在77K和室温条件先非有意掺杂浓度、迁移率、导电率特性。发现随着温度的升高,分子束外延生长的中波、长波、甚长波红外吸收区材料都出现了导电类型由p型向n型的转变,其中中波、长波、甚长波样品的转变温度分别为210、140和85 K,相应的电子激活能为106、71和32 meV。

Boundary element-containing III-V optoelectronic materials have gradually became one of new material systems. However, fewer countries have carried out related researches in this area. In current stage, there are still so many unknown understanding in basic properties, synthesis and devices applications of such materials, which need to be investigated and promoted. With such intention, we carry out the basically innovative research on theoretical calculations, synthesis and characterization of boundary element-containing III-V materials in this project. In theoretical research, electronic structures and optical properties of Ga N1-x Bix and In P1-xB ix ternary alloys have been calculated and analyzed using first-principles, the influence of bismuth incorporation on the physical properties of such alloys have been predicted. In synthesis and characterization of III-V boron-containing materials, BGa As Sb quaternary alloys and BGa As Sb/Ga As MQW have been grown on Ga As by metal-organic chemical vapor deposition. The influence of boron incorporation on Sb incorporation as well as the PL properties of Ga As Sb/Ga As MQW has been found. We have demonstrated a short wavelength（SW）, a mid wavelength（MW） and very-long（VLW） photodetectors using type-II In As/Ga Sbsuperlattice（SL） materials. For all the detection wavelengths, very high-quality type-II In As/Ga Sb SL materials have been grown by molecular beam epitaxy. For the SW device, at 77 K, the achieved 50% cutoff wavelength is 2.56 μm and the peak detectivity D＊ is 1.3×1011 cm·Hz1/2·W^（-1）. For the SW device, a t 77 K, the 50% cutoff wavelength of the device is 4.8 μm and the peak detectivity reaches 2.4×1011 cm·Hz1/2·W-1. For the VLW device, at 77 K, the 50% cutoff wavelength is 14.5 μm and the corresponding quantum efficiency is 14%. The Johnson noise limited detectivity D＊ is 4.3×109 cm·Hz1/2·W^（-1） at 14.5 μm.We investigate the background doping level, mobility and conductivity of the absorber layer using the type-II In As/Ga Sb structure grown by molecular beam epitaxy for the MW, LW and VLW bands between 77 K and room temperature. It is found that the conduction of the absorber layer changes from p- to n-type when increasing temperature. The transition temperature occurs at 210, 140 and 85 K and the electron activation energy is 106, 71 and 32 meV for the MW, LW and VLW samples, respectively.