In this study, InGaN/GaN heterostructures were grown on a c-plane flat sapphire substrate (FSS) by using the metalorganic chemical vapor deposition (MOCVD) technique. The flow rates of the ammonia gas varied from 9 SLM to 24 SLM for the growth of InGaN thin film, which was equivalent to the V/III ratio of 6211–16562. Results indicated that a higher V/III ratio promotes parasitic behavior by hydrogen dissociated from ammonia. The parasitic behavior from hydrogen species etches the InN away from the growing surface and transforms the growth morphology from 3D islands to 2D growth mode. A slight reduction in indium composition was observed when increasing the V/III ratio. Next, more stable bandgap energy was observed for the InGaN thin films grown at higher V/III ratios. Improvements in electrical properties in terms of electron mobility and sheet resistance were observed at a higher V/III ratio which is associated with the improvement of crystalline quality and less defect density at a higher V/III ratio. The correlation of strain and carrier density of the thin films was further discussed. It was concluded that the growth of high crystalline quality and thick InGaN thin film was possible for solar cell applications at higher V/III ratio growth conditions.

在这项研究中，InGaN/GaN 异质结构生长在c-平面平面蓝宝石衬底 (FSS) 通过使用金属有机化学气相沉积 (MOCVD) 技术。对于 InGaN 薄膜的生长，氨气的流量从 9 SLM 到 24 SLM 不等，相当于 V/III 比为 6211–16562。结果表明，较高的 V/III 比会促进从氨中解离的氢的寄生行为。来自氢物种的寄生行为将 InN 蚀刻远离生长表面，并将生长形态从 3D 岛转变为 2D 生长模式。当增加 V/III 比时，观察到铟成分略有减少。接下来，对于以较高 V/III 比生长的 InGaN 薄膜，观察到了更稳定的带隙能量。在较高的 V/III 比下观察到电子迁移率和薄层电阻方面的电性能改善，这与晶体质量的改善和较高 V/III 比下缺陷密度的降低有关。进一步讨论了薄膜应变与载流子密度的相关性。得出的结论是，在更高的 V/III 比生长条件下，对于太阳能电池应用来说，高结晶质量和厚 InGaN 薄膜的生长是可能的。