Thin film solar cell module

A thin film solar cell module comprising a first solar cell panel containing an array of solar cells consisting of a TFS semiconductor sandwiched between a transparent conductive zinc oxide layer and a transparent conductive layer selected from the group consisting of tin oxide, indium tin oxide, and zinc oxide deposited upon a transparent superstrate,

• and a second solar cell panel containing an array of solar cells consisting of a CIS semiconductor layer sandwiched between a zinc oxide semiconductor layer and a conductive metal layer deposited upon an insulating substrate, said zinc oxide semiconductor layer containing a first relatively thin layer of high resistivity zinc oxide adjacent said CIS semiconductor and a second relatively thick layer of low resistivity zinc oxide overlying said high resistivity zinc oxide layer, said transparent conductive zinc oxide layer of said first panel facing said low resistivity zinc oxide layer of said second panel, said first and second panels being positioned optically in series and separated by a transparent insulating layer.