本文研究了AlGaAs和GaAs异质结太阳能电池的分子束外延生长及其光电特性。在调研了国内外GaAs太阳能电池研究现状基础上，首先对影响太阳能电池性能的关键参数如少子扩散长度、掺杂浓度、背面场、窗口层等进行了细致的理论分析与模拟，并以此为指导设计了单节和双节电池。通过RHEED、IV特性曲线、AFM等测试方法，分析了生长温度、Ⅲ/Ⅴ束流比等参数对MBE生长的外延层质量的影响，研究发现采用较低生长温度和较高Ⅲ/Ⅴ束流比可以有效抑制P型掺杂剂Be在外延层中的扩散，获得了高掺杂隧道结材料，其隧穿电流密度的峰值达284.10A/cm2，面电导率达684.56 A/Vcm2。

This paper mainly focused on the molecular beam epitaxy (MBE) growth and characterization of the AlGaAs and GaAs herterostructure solar cells. Starting from a survey of current development about the solar cells, the influences of key parameters such as minority carrier diffusion length, doping concentration, buffer and window layers on device performance were theoretically analyzed and modeled, and thus single and double heterostructure solar cells were proposed for experiments. By applying RHEED, IV curve and Atomic Force Microscopy measurements the effects of growth temperature and As/Ga flux ratio on the qualities of the expitaxy layers were investigated. It was found that under lower growth temperature and higher Ga-As flux ratios, the diffusion of Be in GaAs layer was restrained effectively. Finally, highly doped tunnel junction with peak current density of 284.10A/cm2 and the special conductivity of 684.56A/Vcm2 as achieved .