Abstract Due to Silicon (Si) material abundance and lower cost, integration of high efficiency III-V solar cells on Si substrates is of major importance for future solar energy harvesting devices. In this paper, we report on the growth optimization with a detailed characterization of epitaxial growth of crystalline GaAs on porous silicon layers (PSL), and demonstration of single-junction GaAs solar cell on PSL performances. GaAs deposition is performed on engineered porous Si surfaces with different growth temperatures. One and two-steps growth (TSG) were also investigated. X-ray diffraction demonstrated almost one order of magnitude lower threading dislocation density (TDD) of 2× 108 cm-2 for TSG process of GaAs on PSL compared to the one-step growth. Atomic Force Microscopy and Scanning Electron Microscopy showed that a reduction of growth temperature leads to surface morphology improvement. A single junction GaAs solar cell heterostructure grown by TSG and fabricated atop the porous layer, demonstrated higher open-circuit voltage (Voc) and fill factor (FF) when compared to an identical structure grown on crystalline Si (c-Si).

中文翻译：

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通过介孔 Si 缓冲液在 Si 衬底上直接生长 GaAs 太阳能电池

摘要 由于硅 (Si) 材料丰富且成本较低，在硅基板上集成高效 III-V 族太阳能电池对于未来的太阳能收集设备具有重要意义。在本文中，我们报告了生长优化，详细描述了晶体 GaAs 在多孔硅层 (PSL) 上的外延生长，并演示了单结 GaAs 太阳能电池对 PSL 性能的影响。GaAs 沉积是在具有不同生长温度的工程多孔硅表面上进行的。还研究了一步和两步生长 (TSG)。X 射线衍射表明，与一步生长相比，PSL 上 GaAs 的 TSG 工艺的穿透位错密度 (TDD) 几乎降低了一个数量级，为 2×108 cm-2。原子力显微镜和扫描电子显微镜显示生长温度的降低导致表面形态改善。与在晶体硅 (c-Si) 上生长的相同结构相比，由 TSG 生长并在多孔层顶部制造的单结 GaAs 太阳能电池异质结构表现出更高的开路电压 (Voc) 和填充因子 (FF)。