Study of Cd-free buffer layers using In-x(OH,S)(y) on CIGS solar cells

The alternative buffer layer material In-x(OH,S)(y) was deposited on Cu(In, Ga)Se-2 (CIGS) thin films by chemical-bath-deposition (CBD). The impurities in In-x(OH,S)(y) buffer layers and their atomic concentration were charact erized by X-ray photoelectron spectroscopy (XPS) and Auger electron spectro scopy (AES) analyses. In addition, AES was used to depth profile the sample s. The band-gap energy of the deposited In-x(OH,S)(y) was determined from o ptical absorption data. Both the dark- and photo-current-voltage (I-V) char acteristics of the CIGS solar cells with In-x(OH,S)(y) buffer layers were m easured, and the results were compared to the CIGS cells deposited with CBD CdS buffer layers. (C) 2001 Elsevier Science B.V. All rights reserved.