A1_xGa_（1－x）As／GaAs太阳电池的结构观察和器件性能

Structure and Device Characteristic of Al_xGa_(1-x)As/GaAs Solar Cells

运用不同的液相外延（ＬＰＥ）生长工艺，制备了两种结构的ＡｌｘＧａ１－ｘＡｓ／ＧａＡｓ太阳电池，并结合透射电子显微镜（ＴＥＭ）等技术分析了外延工艺对器件性能的影响。结果表明，与过冷生长技术相比，回熔工艺对衬底质量的要求不严格，且能形成有利于光生少子被收集的带隙结构。在工艺优化的情况下，我们所获得太阳电池的全面积转换效率在ＡＭ０，１ｓｕｎ条件下为１８．７８％（０．７２ｃｍ２），在ＡＭ１．５，ｌｓｕｎ条件下为２３．１７％。

AlxGa1-xAs/GaAs heterostructure has been grown by two different liquid phase epitaxy(LPE) methods for the fabrication of solar cells. Typical structure characteristics observed under transmission electron microscopy(TEM) and the corresponding device parameters are presented. The results indicate that the P+PNN+ configuration grown by meltback-regrowth method can effectively reduce the defects of the substrate and improve the minority carrier collection by forming a composition-graded region in the window layer. By optimizing the growth conditions and device technology, the best cell performance with conversion efficiency of 18. 78% under AMO,lsun or 23. 17% under AM1. 5, lsun conditions is exhibited.