液相外延法制备0.55eV-GaInAsSb四元合金薄膜及其在热光伏器件中的应用

利用液相外延法(LPE)在n型GaSb衬底上成功制备了用于热光伏电池的Ga1-xInxAsySb1-y四元合金薄膜.通过原子力显微镜对薄膜的表面形貌进行了分析评价.x射线能谱(EDAX)分析表明四元合金薄膜的成分为x=0.2,y=0.17.红外傅里叶变换透射谱分析表明,其室温下的吸收截止波长为2.256μm,对应禁带宽度为0.55eV.室温下的霍尔测试结果表明外延膜具有良好的电学性能,其非故意掺杂的薄膜表现为P型,载流子浓度为6.1×1016 cm-3,迁移率为512cm2/(V·s).又进一步利用Ga1-xInxAsySb1-y薄膜制备了不同结构的GaInAsSb基热光伏电池,光谱响应测试表明其量子效率可达60%.

Growth of 0.55eV-GaInAsSb Quaternary Alloy Films for a Thermophotovoltaic Device by Liquid Phase Epitaxy

Lattice matched Ga1-xInxAsySb1-y quaternary alloy films for thermophotovoltaic cells were successfully grown on n-type GaSb substrates by liquid phase epitaxy. Mirror-like surfaces for the epitaxial layers were achieved and evaluated by atomic force microscopy. The composition of the Ga1-xInxAsySb1-y layer was characterized by energy dispersive X-ray analysis with the result that x = 0.2, y = 0.17. The absorption edges of the Ga1-xInxAsySb1-y films were determined to be 2. 256μm at room temperature by Fourier transform infrared transmission spectrum analysis, corresponding to an energy gap of 0.55eV. Hall measurements show that the highest obtained electron mobility in the undoped p-type samples is 512cm2/(V·s) and the carrier density is 6. 1×1016cm-3 at room temperature. Finally, GaInAsSb based thermophotovoltaic cells in different structures with quantum efficiency values of around 60% were fabricated and the spectrum response characteristics of the cells are discussed.