PERSPECTIVE ON HIGH-EFFICIENCY CU(IN,GA)SE-2-BASED THIN-FILM SOLAR-CELLS FABRICATED BY SIMPLE, SCALABLE PROCESSES

We have fabricated high-efficiency Cu(In, Ga)Se-2(CIGS)-based photovol taic (PV) devices by four different processes, Each process may be cha racterized as either sequential or concurrent deposition of the metals with or without an activity of selenium. A world-record total-area ef ficiency of 17.1% has been achieved by the concurrent delivery of the metals in rite presence of selenium. Gallium has been introduced into rite device in such a manner as to produce homogeneous, normal profili ng and double-profiling graded bandgap structures. This has resulted i n an open-circuit voltage (V-oc) parameter of 680 mV and a fill factor of over 78%, A growth model has been developed allowing for simple tr anslation of these processes to a manufacturing environment for the la rge-scale production of modules.