Perspective on High‐efficiency Cu(In, Ga)Se2‐based Thin‐film Solar Cells Fabricated by Simple, Scalable Processes

Abstract

AbstractWe have fabricated high‐efficiency Cu(In, Ga)Se2(CIGS)‐based photovoltaic (PV) devices by four different processes. Each process may be characterized as cither sequential or concurrent deposition of the metals with or without an activity of selenium. A world‐record, total‐area efficiency of 17.1% has been achieved by the concurrent delivery of the metals in the presence of selenium. Gallium has been introduced into the device in such a manner as to produce homogeneous, normal profiling and double‐profiling graded bandgap structures. This has resulted in an open‐circuit voltage (Voc) parameter of 680 mV and a fill factor of over 78%. A growth model has been developed allowing for simple translation of these processes to a manufacturing environment for the large‐scale production of modules.