Antimony assisted low-temperature processing of CuIn1-xGaxSe2-ySy solar cells

Application of the Sb-doping method to low-temperature (<= 400 degrees C) processing of CuIn1-xGaxSe2-ySy (CIGS) solar cells is explored using a hydrazine-based approach to deposit the absorber films Power conversion efficiencies of 10 5% and 8 4% have been achieved for CIGS devices (0 45 cm(2) device area) processed at 400 C and 360 degrees C respectively with an Sb-incorporation level at 1 2 mol % (relative to the moles of CIGS) Significant Sb-induced grain size enhancement was confirmed for these low processing temperatures using cross-sectional scanning electron microscopy and an average 2-3% absolute efficiency Improvement was achieved in Sb-doped samples compared to their Sb-free sister samples With Sb inclusion the CIGS film grain growth temperature is lowered to well below 450 degrees C a range compatible with flexible polymer substrate materials such as polyimide This method opens up access to opportunities in low temperature processing of CIGS solar cells an area that is being actively pursued using both traditional vacuum-based as well as other solution-based deposition techniques (C) 2010 Elsevier B V All rights reserved