Energy Conversion Devices, Inc.

Other

Sovonics Solar Systems

Arun Madan

Stanford R Ovshinsky

Chi C Yang

David Adler

A method producing a solid semiconductor film characterized by a low density of defect states in the energy gap thereof by the glow discharge deposition of a precursor gaseous mixture which includes a gas chosen from the group consisting essentially of hydrogen, fluorine, or combinations thereof and a compound chosen from the group consisting essentially of SiH.sub.3 F, SiH.sub.2 F.sub.2, SiHF.sub.3, SiHCl.sub.3, SiH.sub.2 Cl.sub.2, SiH.sub.3 Cl, SiCl.sub.3 F, SiCl.sub.2 F.sub.2, SiClF.sub.3, or combinations thereof.

Fluorinated precursors from which to fabricate amorphous semiconductor

A wide band amorphous semiconductor alloy including a host matrix of silicon and incorporating therein carbon or nitrogen and a plurality of different and complimentary density of states reducing elements.

Wide band gap semiconductor alloy material

A photodetection device and a current control device, both including means responsive to the intensity of incident radiation for providing an output signal corresponding thereto. The responsive means includes a thin semiconductor film comprising a solid amorphous silicon or amorphous germanium host matrix having electronic configurations and an energy gap. At least one compensating element is introduced into that matrix for reducing the density of states in the energy gap thereof.

Photodetection and current control devices

An amorphous semiconductor body, most advantageously a glow discharge deposited silicon-containing host matrix film, is provided containing at least fluorine as a compensating or altering agent, and most preferably at least one complementary compensating or altering agent, such as hydrogen, both of which reduce the localized defect states in the energy gap of the amorphous semiconductor material to a degree which either one alone could not achieve. The silicon and/or other elements of the host matrix film are deposited by the glow discharge decomposition of gaseous compounds preferably with fluorine as one element of a compound, the hydrogen and other compensating and altering material being preferably a molecular gas or an element of a compound of silicon or other host matrix element.

Amorphous semiconductors equivalent to crystalline semiconductors

The production of improved photoresponsive amorphous alloys and devices, such as photovoltaic, photoreceptive devices and the like; having improved wavelength threshold characteristics is made possible by adding one or more band gap increasing elements to the alloys and devices. The increasing element or elements are added at least to a portion of the active photoresponsive regions of amorphous silicon devices. One increasing element is carbon which increases the band gap from that of the materials without the increasing element incorporated therein. Other increasing elements can be used such as nitrogen. The silicon and increasing elements are concurrently combined and deposited as amorphous alloys by vapor deposition, sputtering or glow discharge decomposition. A density of states reducing element allows the band gap increasing element(s) to be added to the alloy to adjust the band gap without reducing the electronic qualities of the alloy. The compensating or altering element(s) can be added during deposition of the alloy or following deposition. The addition of the increasing element(s) to the alloys increases the band gap to a widened utilization width for a particular device to increase the photoabsorption efficiency and to thus enhance the device photoresponse. The band gap increasing element(s) can be added in varying amounts, in discrete layers or in substantially constant amounts in the alloys and devices.

P-type semiconductor material having a wide band gap

P-Type semiconductor material having a wide band gap

The disclosure is directed to photovoltaic devices having enhanced short circuit currents and efficiencies. The devices are made by depositing on a previously deposited doped amorphous semiconductor alloy layer a body of intrinsic amorphous semiconductor alloys including a first intrinsic layer, adjacent the doped layer, formed from the deposition of a non-etching starting material and a second intrinsic layer different in composition from the first intrinsic layer. The second intrinsic layer preferably includes silicon and fluorine while the first intrinsic amorphous alloy layer does not include fluorine. The first intrinsic layer may be formed by the glow discharge decomposition of silane gas alone. The thicknesses of the first and second intrinsic layers are adjusted so as to match the respective potential drops thereof with the first intrinsic layer being relatively thin as compared to the second intrinsic layer.

Current enhanced photovoltaic device

A method of making an amorphous semiconductor film or the like having desirable photoconductive and/or other properties comprises depositing on a substrate a solid amorphous semiconductor film including at least one element, by glow discharge decomposition of a compound containing said at least one element and at least one alterant element in an atmosphere separately containing at least one different alterant element, wherein the plurality of different alterant elements comprise at least fluorine and are incorporated in said amorphous semiconductor film during the deposition thereof yielding an altered amorphous semiconductor material having reduced density of localized states in the energy gap thereof so that greatly increased diffusion lengths for solar cell application are obtained and modifiers or dopants can be effectively added to produce p-type or n-type amorphous semiconductor films so that the films function like similar crystalline semiconductors.

Growing community of inventors

Birmingham, MI, United States of America

Arun Madan