P-InP Surface Modification Due to Indium Tin Oxide Deposition
P-InP Surface Modification Due to Indium Tin Oxide Deposition

Author: Pete Sheldon

Publisher:

Published: 1982

Total Pages: 7

ISBN-13:

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Indium tin oxide (ITO)/InP solar cells have achieved efficiencies of over 14%. Several previous studies have attempted to characterize the ITO/InP junction. In all cases, the electrical properties of this device have been linked to possible compositional changes at or near the interface region. Various models of the junction have been proposed, including the SIS and buried homojunction structures. In this paper, we examine the compositional changes at the InP surface due to ion beam deposition of ITO, using ion microprobe measurements.

Near-Surface Type Conversion of P-type Single-Crystal InP by Plasma Exposure
Near-Surface Type Conversion of P-type Single-Crystal InP by Plasma Exposure

Author: X. Li

Publisher:

Published: 1992

Total Pages: 4

ISBN-13:

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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.