外延GaNAs薄膜价带分裂随温度变化的研究  

Study on Temperature Dependence of the Valence Band Splitting of the Epitaxy GaNAs Thin Films

作　　者：陈雪梅[1,2] 唐利斌[2] 万锐敏[2] 王茺[1] 杨宇[1] 

机构地区：[1]云南大学工程技术研究院光电信息材料研究所,昆明650091 [2]昆明物理研究所基础研发部,昆明650223

出　　处：《材料导报》2010年第20期31-34,共4页Materials Reports

基　　金：云南大学理工基金资助项目(2009E27Q);教育部重点项目(210207);兵器预研支撑项目(62301110105)

摘　　要：利用分子束外延(MBE)技术在GaAs(001)衬底上生长了GaN0.01As0.99薄膜,然后使用光调制反射(PR)光谱研究了薄膜的光学性质和能带结构。PR光谱实验表明GaN0.01As0.99/GaAs薄膜价带在Γ点发生轻、重空穴分裂,且分裂的轻、重空穴带到导带边的2个跃迁峰随着温度的升高均发生红移。采用Varshni法则、Bose-Einstein关系和BAC模型分别对轻、重空穴的能隙分裂和红移特征进行了拟合。分析结果表明,随着温度的升高,Ga-NAs外延层与GaAs衬底间晶格失配的减少可能是导致应变能和价带分裂能量减少的主要因素。The epitaxy GaN0. 01 As0.99 thin film is grown by the molecule beam epitaxy（MBE） technique, and is investigated by the photoreflectence（PR） spectroscopy in a wide temperature range. The PR experiments indicate that the light and heavy hole band undergo a splitting at P point, and the optical transitions from both light and heavy hole to the conduction band edge red-shift with the increase of temperature. The fitting experiments are preformed for the PR spectra based on the Varshni law, Bose-Einstein relation, and band anticross model. The analytical results indicate that the reduction of lattice mismatch with increase of temperature is the key factor to induce the reduction of the strain energy and the splitting energy.

关 键 词：GaNxAs1-x薄膜 价带分裂 晶格膨胀 温度 

分 类 号：O562.1[理学—原子与分子物理]