Solar cells and method for making same
AssigneeWestinghouse Electric Corp.
InventorFred A. Shirland
Life of this patent
Estimating the term…
Abstract
Solar cell elements are produced in accordance with the present invention in which a Cu.sub.2 S thin film is epitaxially formed on a CdS film by vacuum deposition in a heterojunction forming relationship. By a first method a Cu.sub.2 S layer on the order of 1/100 micron in thickness is formed on a CdS polycrystalline thin film by dipping in a solution of cuprous ions. The CdS film itself is less than 5 microns thick and rests on a conductive substrate. After the dipping step the Cu.sub.2 S film is increased to a thickness on the order of 1/10 micron by vapor evaporation of an additional amount of Cu.sub.2 S. By a second method both the CdS and Cu.sub.2 S are entirely vapor deposited on a substrate to achieve approximately the same final structure as the first method.
Claims6
A method for making a solar cell structure comprising the steps:
- a. dipping a polycrystalline CdS thin film into a solution containing cuprous ions, thereby forming a first polycrystalline Cu.sub.2 S thin film layer on said CdS film and
- b. depositing a second Cu.sub.2 S layer on said first Cu.sub.2 S layer by vacuum deposition.
A method for making a solar cell structure comprising the steps:
- a. depositing a polycrystalline thin film layer of CdS on a conductive substrate by vacuum deposition;
- and
- b. abruptly halting said CdS deposition while simultaneously abruptly initiating vacuum deposition of a polycrystalline thin film layer of Cu.sub.2 S on said CdS layer.
A solar cell comprising a conductive substrate, a polycrystalline CdS thin film layer disposed on said substrate, a polycrystalline Cu.sub.2 S thin film layer disposed on said CdS layer, said Cu.sub.2 S layer comprising an ion-exchange produced first thin portion penetrating only partly into the grain boundaries of the CdS layer and a vapor deposited second portion overlying said first thin portion, said second portion exceeding said first portion in thickness.
Dependencies are inferred from the claim text.