[19a-F310-1~8] 13.9 Compound solar cells

▲ [19a-F310-3] Effects of V/III ratio on the quality of GaAs grown by MOVPE with extremely-high growth rate

〇Hassanet Sodabanlu¹, Akinori Ubukata², Kentaroh Watanabe¹, Takeyoshi Sugaya³, Yoshiaki Nakano⁴, Masakazu Sugiyama^1,4 (1.RCAST, Univ. of Tokyo, 2.Taiyo Nippon Sanso Corp., 3.AIST, 4.School of Engineering, Univ. of Tokyo)

Keywords:GaAs, MOVPE, III-V solar cells

Much effort has been devoted recently to reduce the cost of GaAs based solar cells including the epitaxy cost, generally by metalorganic vapor phase epitaxy (MOVPE). Our previous study showed GaAs PV cells deposited at 90 µm/h by MOVPE using a V/III ratio of 40 without significant degradation of cell efficiency. As a further step to reduce the material cost, effects of V/III ratio on the quality of GaAs grown at an extremely high growth rate have been thoroughly investigated in this work. Good surface morphology could be realized even with a low V/III ratio of 5. A long minority hole lifetime in n-doped GaAs was also achieved. The results have not evidenced a significant change in quality as a function of V/III ratio. Further studies would focus on the influence of low V/III ratio on the performance of GaAs solar cells grown at 90 µm/h.