Extremely lightweight, flexible semiconductor device arrays

Abstract

An extremely lightweight, interconnected array of semiconductor devices, such as solar cells, is formed from a large continuous area of semiconductor material disposed on an unconventionally thin, electrically conducting substrate. The interconnections are formed by removing portions of the substrate to form substrate islands underlying a layer of semiconductor material which underlies a transparent conductive oxide. The oxide layer may likewise be formed into mutually isolated islands that overlay the areas between the substrate islands. Individual units or cells so formed may be interconnected by depositing a conducting material on, alongside and at least partially between islands of oxide and/or semiconductor, by depositing a metal grid on the oxide layer and burning conducting paths to the substrate islands, or by piercing the layers and disposing a conducting material in the holes pierced. The unconventionally thin substrate may be a sheet of electroformed nickel or other thin metal or an initially thick substrate that is thinned by chemical etching after other array processing steps are completed. An encapsulant is preferably applied to the exposed surface of the semiconducting material to protect it while the substrate is being thinned or removed. Subsequently, an encapsulant is applied to the rear of substrate side of the array.