1997 Fiscal Year Final Research Report Summary
Electrochomicel Processing of II-VI Group Semiconductor Cempound
| Project/Area Number |
08455347
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Metal making engineering
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
FUKUNAKA Yasuhiro Dept.of ENERGY SCIENCE & TECHNOLOGY Associate Professor, エネルギー科学研究科, 助教授 (60111936)
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| Project Period (FY) |
1996 – 1997
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| Keywords | Compound Semiconductor / Electrochemical Processing / Electrodeposition Mechanism / Calcogenite / Induced Codeposition / solas Cell |
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| Research Abstract |
CdTe alloy film was potentiostatically electrodeposited on a rotating disk electrode. The effects of overpotentia1, pH and sometimes HTeO_2^+ concentration or temperature were examined over wide range of electrolytic conditions. The deviation from stoichiometry was not always negligible. When the electrolysis was conducted at 60ﾟC, CdTe compound semiconductor film was obtained in electrolyte of pH=l.6 and 2 at eta= 33OmV.At 80ﾟC, pH region was shifted to pH=l and 1.5. The preferred orientation of CdTe film was the (111) plane. A significant induced codeposition phenomena for Cd was observed at pH=1. It was, moreover, noticed that the existence of HTeO_2^+ ion at the cathode surface hindered the hydrogen gas bubble evolution rate.
From the phenomenological similarity between the amorphous film electrodeposition of metal/metalloid system and the semiconductor film of metal/chalcogen system, the adsorption mechanism was applied. The ionic mass transfer rate was calculated to estimate the surface concentrations of various species. The composition of electrodeposited CdTe film was reasonably correlated with the calculated surface concentration of HteO_2^+ ion. These experiments suggested that the surface diffusion rate of metal incorporated into the crystal lattice must be accommodated at an appropriate rate by the existence of adsorbed species, when the microstructure film is electrochemically processed.
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