Semiconductor optical detector structure

Abstract

A semiconductor is disclosed with a substrate doped with a substrate doping. There is a crystalline semiconductor layer disposed on a front side of the substrate. The crystalline semiconductor layer has a layer doping. The substrate doping changes to the layer doping within a 100 angstrom transition region. In alternative embodiments, the layer doping has novel profiles. In other alternative embodiments, the substrate has a crystalline semiconductor layers disposed on each of a front and a back side of the substrate. Each of the crystalline semiconductor layers has a respective layer doping and each of these layer dopings changes to the substrate doping within a respective transition region less than 100 angstroms thick. In still other embodiments of this invention, an amorphous silicon layer is disposed on a side of the crystalline semiconductor layer opposite the substrate.; The amorphous silicon layer has an amorphous doping so that a tunnel junction is formed between the doped crystalline semiconductor layer and the amorphous layer. Manufacturing these structures at below 700 degrees Centigrade enables the narrow transition regions of the structures.

Description

[0001] Cross References to Related Applications [0002] This application is related to an application entitled "Method of Making a Semiconductor Optical Detector Structure" filed on the same date by the same inventor as this application, the entire contents of which are hereby incorporated by reference. [0003] This application claims priority to Provisional Patent Application Serial No. 61 / 219,131, filed June 22, 2009, entitled "Low Cost, Low Thermal Budget Solar Cells." technical field [0004] The present invention relates to semiconductor optical detector structures. More particularly, the present invention relates to low temperature fabricated solar cell structures. Background technique [0005] Solar cells are a promising approach to enhancing the world's energy supply. Silicon-based solar cells are currently the dominant photovoltaic technology. Silicon solar cells can be produced starting from semiconductor wafers, wherein the semiconductor wafers can consist of...

AI Technical Summary

Problems solved by technology

Although such cells can be fabricated using temperatures below 900 degrees Celsius, the quality of tandem junction cells is strongly limited by the poor quality of the microcrystalline fraction, which has a grain size much smaller than 1 micron and is often is less than 0.1 microns

Therefore, the efficiency of tandem junction cells is limited to values ​​less than about 12%

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