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Transparent Conducting Oxides Based on the Spinel Structure
Author(s) -
Kawazoe Hiroshi,
Ueda Kazushige
Publication year - 1999
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1999.tb02247.x
Subject(s) - spinel , ion , materials science , vacancy defect , ion implantation , thermal conduction , chemical physics , optoelectronics , chemistry , crystallography , metallurgy , composite material , organic chemistry
The structural characteristics of spinel (from both theoretical and experimental viewpoints) that are advantageous for producing transparent conducting oxide (TCO) materials are considered. A working hypothesis is presented for finding new TCO materials with spinel structure. Results of tight‐binding energy‐band calculations reveal the formation of extended conduction bands in selected TCOs. This is a necessary criterion for n ‐type TCOs containing cations with d 10 s 0 electronic configuration. Discovery of some transparent conducting spinels, namely MgIn 2 O 4 , CdGa 2 O 4 , and ZnGa 2 O 4 , provides experimental confirmation for the formation of extended conduction bands. Li + ‐, He + ‐, and H + ‐ion implantations into MgIn 2 O 4 films have been performed to explore a new technique to generate electron carriers. Carrier generation in implanted MgIn 2 O 4 films has been verified from electrical conductivity and optical absorption measurements. Implanted Li + ions have been observed to occupy vacant tetrahedral cation interstices in the spinel lattice. Each Li + ion releases an electron to the conduction band upon occupying this tetrahedral vacancy. Observations suggest that the ion implantation technique is effective and feasible for carrier generation in TCO materials.