Polycrystalline photovoltaic cell
AssigneePhoton Power, Inc.
InventorVijay P. Singh
Life of this patent
Estimating the term…
Abstract
A photovoltaic cell is formed by combining a spray process, forming a crystalline layer containing cadmium and sulfur, and an evaporation process, depositing copper chloride for converting to Cu.sub.x S. The crystals containing cadmium and sulfur are heated in an atmosphere of cadmium and chlorides to obtain crystals having at least one dimension greater than 0.5 micron and a planar layer of Cu.sub.x S is formed on the large crystals. A layer of Cu.sub.x S having a thickness of 0.5-1.0 micron is obtained. Electrodes are formed from evaporated gold or chromium or a metallic paste including silver or copper. Zn.sub.x Cd.sub.1-x S may be substituted for CdS through at least part of the crystalline layer for improved Voc.
Claims15
A photovoltaic cell formed in a backwall configuration on a transparent vitreous substrate and over a transparent electrically conductive film, comprising:
- a crystalline film containing cadmium and sulfur and having crystals with at least one dimension greater than 0.5 micron formed to a first thickness in the range of 1-6 microns, and
- a film of Cu.sub.x S forming a substantially planar heterojunction with said crystalline film containing cadmium and sulfur and having a thickness in the range of 0.5-1.0 microns,
- said first thickness being effective to maintain a depletion layer formed from and adjacent said heterojunction from contacting said electrically conductive film.
A photovoltaic cell formed in a backwall configuration on a transparent vitreous substrate and over a transparent electrically conductive film, comprising:
- a crystalline film containing CdS and having crystals with at least one dimension greater than 0.5 micron formed to a first thickness,
- a film of Cu.sub.x S forming a substantially planar heterojunction with said crystalline film containing CdS and having thickness in the range of 0.5-1.0 microns,
- a first portion of said crystalline film adjacent said electrically conductive film including CdS, and
- a second portion of said crystalline film including Zn.sub.x Cd.sub.1-x S and forming said heterojunction with said Cu.sub.x S,
- said first thickness being effective to maintain a depletion layer formed from and adjacent said heterojunction from contacting said electrically conductive film.
Dependencies are inferred from the claim text.