Patent ID: 8134069

Claim:
A solar cell, comprising: a metal or plastic substrate which does not provide an available supply of sodium; a first electrode located over the substrate, wherein the first electrode comprises a first transition metal layer containing: (i) a transition metal, (ii) an alkali element or an alkali compound, and (iii) a lattice distortion element or a lattice distortion compound; at least one p-type semiconductor absorber layer located over the first electrode, wherein the p-type semiconductor absorber layer includes a copper indium selenide (CIS) based alloy material; an n-type semiconductor layer located over the p-type semiconductor absorber layer; and a second electrode located over the n-type semiconductor layer, wherein a concentration of the alkali element or alkali compound in the transition metal layer is greater than the concentration of the alkali element or alkali compound in the at least one p-type semiconductor absorber layer.