Effects of growth interruption on InGaP fabricated via hydride vapor phase epitaxy

Abstract

Hydride vapor phase epitaxy (HVPE) is a promising technique for reducing the high cost associated with the fabrication of high-performance III–V solar cells. We studied the effects of growth interruption on InGaP single-junction solar cells fabricated via HVPE. Our HVPE reactor contains two growth chambers and a preparation chamber. The preparation chamber is where the substrate waits under AsH3 or PH3 until the gas flows are stabilized in the next growth’s chamber. In this study, we focus on the effects of the distance from the preparation chamber to the substrate (dpre) and the growth interruption time (tGI) on InGaP/InGaP interfaces. Rough interfaces were formed owing to cross-contamination from other chambers for a sample grown with nonoptimized dpre. In contrast, abrupt InGaP/InGaP interfaces were obtained for a sample grown by decreasing dpre. Furthermore, we found that the tGI affects the device performance when switching the dopant gas from DMZn to H2S.