4:15 PM - 4:30 PM
[7p-S21-13] Highly uniform, low-cost III-V solar cells grown with hydride vapor phase epitaxy
Keywords:III-V compound semiconductor, Solar cells, Hydride vapor phase epitaxy
To date, the use of highly efficient III-V multijunction devices has been limited to space and high-concentration terrestrial systems owing to their extremely high manufacturing cost. We developed a hydride vapor phase epitaxy (H-VPE) system with horizontal flow for low cost III-V solar cell fabrication. In this study, we evaluated the effects of the homogeneity of the gas flow pattern on the growth surface on the thickness and performance of the GaAs solar cells. The thickness uniformity was found to be as high as 30.1% in the case of conventional growth. In addition, the thickness was greater towards the lower end, suggesting that the reactant concentration was higher in the lower region of the growth chamber, owing to the gas flow being inhomogeneous because of the unoptimized reactor design and the specific gravity of the various gas species. By modifying the shape of the nozzle of the growth chamber, the thickness uniformity could be reduced significantly to 3.2%, owing to the improved uniformity of the gas flow pattern. Furthermore, it could be improved further, to 2.5%, by rotating the substrate during growth.