In this study, the epitaxial growth of co-evaporated Cu(In,Ga)Se₂ films (CIGSe) onto GaP/Si(001) pseudo-substrates, where the GaP thin layer is epitaxially grown by Molecular Beam Epitaxy (MBE), is investigated. Extensive structural characterisation of epi-CIGSe is carried out via X-ray diffraction as well as transmission electron microscopy. Sturdy evidence of an epitaxial growth of CIGSe on (GaP/Si)(001) is observed, with the propagation of twins originating from the GaP/Si interface, through the CIGSe/GaP interface. This work aims at paving the way for future CIGSe/GaP/Si structures for the development of tandem solar cells with a c-Si bottom cell, and a GaP interfacial buffer layer for band edge engineering, allowing for the monolithic epitaxial growth of high quality CIGSe as a thin film top cell absorber.

在本研究中，共蒸发 Cu(In,Ga)Se ₂的外延生长薄膜 (CIGSe) 到 GaP/Si(001) 伪衬底上，其中 GaP 薄层通过分子束外延 (MBE) 外延生长，进行了研究。Epi-CIGSe 的广泛结构表征是通过 X 射线衍射和透射电子显微镜进行的。观察到 CIGSe 在 (GaP/Si)(001) 上外延生长的可靠证据，孪晶的传播源自 GaP/Si 界面，通过 CIGSe/GaP 界面。这项工作旨在为未来的 CIGSe/GaP/Si 结构铺平道路，以开发具有 c-Si 底部电池的串联太阳能电池和用于带边工程的 GaP 界面缓冲层，从而实现高质量的单片外延生长CIGSe 作为薄膜顶部电池吸收剂。