兼容集成中的新型材料系探索與特殊超晶格結構研究年度報告

馬文全 張艷華 徐應強 王琦

摘 要：含邊緣元素的III-V族光電子合金材料是近些年逐漸興起的一種新型材料系，開展相關研究的國家較少，這些合金的基本特性、合成以及器件應用等方面還存在很多未知，亟需推動。為此，該研究在含邊緣元素的III-V族光電子材料的理論計算、合成實驗與特性表征方面系統地開展基礎創新研究。在理論研究方面，我們利用第一性原理重點計算了GaN1-xBix和InP1-xBix三元合金的電子結構與光學特性等，預測了Bi元素并入對合金物理性質的影響。在III-V族含硼材料的合成與特性表征方面，利用低壓金屬有機化學氣相沉積技術，在GaAs上生長出了BGaAsB四元合金與BGaAsSb/GaAs MQW，明確了B并入對于Sb并入以及GaAsSb/GaAs MQW光致發光特性的影響。基于InAs/GaSb二類超晶格實現短波、甚長波及窄帶長波/甚長波雙色紅外探測器的研究，生長的材料具有極高的材料質量.短波探測器單管器件在77 K條件下50%截止波長為2.56 μm，峰值探測率為1.3×1011 cm·Hz1/2·W-1；中波探測器單管器件在77 K條件下50%截止波長為4.3 μm，峰值探測率為2.4×1011 cm·Hz1/2·W-1；甚長波紅外探測器單管器件在77 K條件下50%截止波長為14.5 μm，量子效率為14%，熱噪聲限制的探測率為4.3×109 cm·Hz1/2 W-1. 研究了分子束外延生長的中波、長波、甚長波波段的InAs/GaSb二類超晶格吸收層材料在77K和室溫條件先非有意摻雜濃度、遷移率、導電率特性。發現隨著溫度的升高，分子束外延生長的中波、長波、甚長波紅外吸收區材料都出現了導電類型由p型向n型的轉變，其中中波、長波、甚長波樣品的轉變溫度分別為210、140和85 K，相應的電子激活能為106、71和32 meV。

關鍵詞：含鉍合金 含硼合金 金屬有機化學氣相沉積 InAs/GaSb二類超晶格 紅外探測器 短波 中波 甚長波

Abstract：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 GaN1-xBix and InP1-xBix 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， BGaAsSb quaternary alloys and BGaAsSb/GaAs MQW have been grown on GaAs by metal-organic chemical vapor deposition. The influence of boron incorporation on Sb incorporation as well as the PL properties of GaAsSb/GaAs MQW has been found. We have demonstrated a short wavelength （SW）， a mid wavelength （MW） and very-long （VLW） photodetectors using type-II InAs/GaSbsuperlattice （SL） materials. For all the detection wavelengths， very high-quality type-II InAs/GaSb 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 InAs/GaSb 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.

Key Words：Bismuth-containing Alloys；Boron-containing Alloys；MOCVD；Type-II InAs/GaSbsuperlattice；Infrared Detectors；Short Wavelength；Mid Wavelength；Very Long Wavelength

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