We propose the inclusion of a novel In(OH)(3):Zn2+ buffer layer for fabricating high-efficiency CIGS solar cells. This buffer layer was deposited using a solution consisting of ZnCl2, InCl(3)(.)4H(2)O, and thiourea. The In(OH)(3):Zn2+ films showed high resistivities of 2.1 x 10(8) Omega cm and transmittance of above 95% in the visible range. We expected two effects due to this new buffer layer: first is the formation of a passivation layer on the CIGS surface and the second is Zn-doping into CIGS layer, resulting in the formation of a buried junction. A cell efficiency of 14.0% (V-OC: 0.575 V, J(SC): 32.1 mA/cm(2), FF: 0.758) was achieved by using an In(OH)(3):Zn2+ buffer layer, without the light soaking effect. (C) 2002 Elsevier Science B.V. All rights reserved.