Patent ID: 9748435
Date: 2017-08-29
CPC Classifications: H01L,Y02E

Claim:
1. A method for forming a photovoltaic device configured for top illumination by solar energy, the method comprising: providing a back contact layer comprising a conductive material; forming a discontinuous back reflector over the back contact layer; forming a thin-film absorber layer over and in electrical contact with the back contact layer, the thin-film absorber layer (i) having a doping polarity and (ii) comprising CdTe, chalcopyrite, or kesterite, wherein (a) the absorber layer makes direct electrical contact to the back contact layer through discontinuities in the discontinuous back reflector, and (b) the discontinuous back reflector is in contact with, but does not form an ohmic contact to, the absorber layer; forming a partner layer over and in electrical contact with the thin-film absorber layer, the partner layer having a doping polarity opposite that of the thin-film absorber layer, the partner layer and thin-film absorber layer thereby forming a p-n junction; forming a front contact layer disposed over and in electrical contact with the partner layer, wherein (i) the front contact layer comprises a transparent conductive oxide, and (ii) the discontinuous back reflector is positioned to reflect solar energy passing through the front contact layer and the absorber layer back toward the absorber layer; and forming a discontinuous passivation layer disposed between the partner layer and the front contact layer, the front contact layer making electrical contact with the partner layer only through discontinuities in the discontinuous passivation layer; and providing a transparent superstrate over the front contact layer, the transparent superstrate being electrically insulating, wherein, between the discontinuities in the discontinuous passivation layer, the front contact layer extends, as a continuous layer, over an entirety of the discontinuous passivation layer.