Polycrystalline thin-film photovoltaic technologies: from the laboratory to commercialization

Substantial technical progress has occurred in the area of polycrystalline thin-film photovoltaic technologies based on cadmium telluride (CdTe) and copper indium gallium diselenide (CuInGaS₂ , [CIGS]) in the past few years. We report here the many technical advances made in the area of materials research, device development, manufacturing technology, module and system deployment and testing, and early commercialization activities worldwide related to CdTe and CIGS products for specialty and power applications. Also, the various technical issues related to CdTe and CIS are elucidated. NREL scientists have achieved record total-area efficiency of 15.8% for a novel thin-film CdTe solar cell, and world-record total-area efficiency of 18.8% has been achieved fora thin-film CIGS, solar cell. Details of cell processing are given. World-record power output of 915 W and aperture-area efficiency of 10.6% have been achieved by BP Solar, Fairfield, California for a thin-film CdTe power module. Also, a world-record aperture-area conversion efficiency of 12.1% for a thin-film CIGSS power module fabricated by Siemens Solar Industries, Camarillo, California. Both efficiencies and power outputs have been independently confirmed by NRFL