Accession Number : ADP007996

Title :   Near-Surface Type Conversion of p-type Single-Crystal InP by Plasma Exposure,

Corporate Author : SOLAR ENERGY RESEARCH INST GOLDEN CO

Personal Author(s) : Li, X. ; Gessert, T. A. ; Coutts, T. J.

Report Date : JUL 1992

Pagination or Media Count : 4

Abstract : During the past several years considerable work has gone into describing why a buried homojunction forms during direct current (dc) magnetron sputter deposition of indium tin oxide (ITO) on single-crystal, p-type InP. Several mechanisms have been suggested to account for the resulting device behavior. Bachmann suggested that type conversion may be due to substitutional doping by Sn, while Tsai et al. believed that sputter damage was a possibility. In our own work, Sn-free ln2O3 was substituted for the ITO, resulting in devices with very similar photovoltaic response to their ITO/InP counterparts, indicating that Sn is not the cause of type conversion. To investigate this junction formation process further, photovoltaic solar cells have been fabricated by exposing p-type InP substrates to a pure hydrogen plasma (without any deposition procedure involved). In this paper we report how this H2 plasma exposure (PE) affects the InP surface properties. The results confirm that deposition is not necessary to cause the type conversion which forms the buried homojunction, and suggest a fabrication process that may be useful with other relevant materials.

Descriptors :   *CHARGE TRANSFER, *INDIUM PHOSPHIDES, CELLS, CONVERSION, CRYSTALS, DAMAGE, DEPOSITION, DIRECT CURRENT, DOPING, FABRICATION, HYDROGEN, INDIUM, JUNCTIONS, MAGNETRONS, MATERIALS, OXIDES, RESPONSE, SINGLE CRYSTALS, SOLAR CELLS, SUBSTRATES, SURFACE PROPERTIES, SURFACES, TIN, PLASMAS(PHYSICS).

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE