【摘要】 用平衡外延生长和反腐蚀生长法制备了Ga_1-xAl_xAs/GaAs太阳电池的外延片。x值能控制在0.8—0.9,p-Ga_1-xAl_xAs与p-GaAs层浓度在1—3×10¹⁸cm^-3,厚度均小于1μm。用此外延片以AuGeNi,CrAu或CrAuZn分别作n型和p型的欧姆接触,在430—450℃之间,n型与p型一起合金化,时间～45秒。在不是最匹配的抗反射层条件下,AM1最高效率为17.8％,一般效率为13—15％。与已报道的数据相比,电池的短路电流还偏低,开路电压波动较大,短波部份的光谱响应也差。对比平衡生长与反腐蚀生长的p-n结特性,它们基本上相近,而反腐蚀重生长法略好一些。更多还原

【Abstract】 The Ga1-xAlxAs/GaAs Multilayer structure is formed by liquid phase epitaxy with and without back etching, with the x value being controlled within the rang of 0.8-0.9. The carrier concentration of both p-GaAs and p-Ga1-xAlxAs layers is 1 -3× 1018 cm-3 and thier thickness is about IMm. The ohmic contacts are made by AuGe-Ni for n-type GaAs and CrAu or CrAuZn alloys for p-type GaAlAs respectively. The ohmic contacts on both sides are alloyed in a single run at 430-450℃ for 45 sec depending on the juncting depth. The highest AMI efficiency obtained is 17.8% without the use of a suitable anti-reflection coating. The photoresponse in short wavelength region, the short circuit current and especially the open circuit voltage are not as good as those reported in recent literatures. In addition to the unsuitable anti-reflection coating and the relatively thick p-Ga1-xAlxAs window layer, the poor diffusion length ol minority carriers and high recombination rate of carriers at the interface or in the junction region are believed also to affect the conversion efficiency adversely. It is shown that LPE growth with back etching yields better results. It is expected that the conversion efficiency could be further increased by using LPE growth of n-GaAs, p-GaAs and p-Ga1-xAlxAs multilayer in a single run. This work is underway presently.更多还原