1995 Fiscal Year Final Research Report Summary
CONTROL OF CONDUCTION BEHAVIOR OF INORGANIC CRYSTALS WITH WIDE BAND GAP
| Project/Area Number |
06453080
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Inorganic materials/Physical properties
|
|---|
| Research Institution | TOKYO INSTITUTE OF TECHNOLOGY (1995)
Okazaki National Research Institutes (1994) |
|---|
Principal Investigator |
KAWAZOE Hiroshi TOKYO INSTITUTE OF TECHNOLOGY,RESEARCH LABORATORY OF ENGINEERING MATERIALS,PROFESSOR, 工業材料研究所, 教授 (80087288)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
UEDA Naoyuki INSTITUTE FOR MOLECULARE SCIENCE,RESEARCH ASSOCIATE, 分子科学研究所, 助手 (00261123)
|
|---|
| Project Period (FY) |
1994 – 1995
|
| Keywords | n-type conducting oxide / transparent electrods / ultra-violet transparent conductor / mixed valence oxide |
|---|
| Research Abstract |
Results obatined in the present study are summarized in the following.
1)Chemical design of n-type conductive and wide gap oxides. Necessary conditions for realizing high mobility of an electron in a conduction band are : A.Complex oxides of p-block cations which have an electronic configuration of (n-1)d^<10>S^0 ; B.Oxygen polyhedra of the cations constitute an edge sharing linear chain which is a highway of an electron ; C.The phase has hopefully a vacant cation site. This is expected to act as a doping site of excess cations.
2)On the basis of the hypothesis MgIn_2O_4, CdGa_2O_4 and ZnGa_2O_4 with spinel structure were selected. These materials were found to be an n-type conductor and transparent for visible light because of wide band gap larger than 3.5eV.
3)Finding of electron-carrier-generation by cation-implantation. Generation of electron carriers in insulating thin film of MgIn_2O_4 by Li^+-or H^+-implantation was observed. An yield of carrier electron was found to be -100%, when the flux of implanted ions was less than 10^<16>cm^<-2>.
4)Some new transparent and conductive oxides with pyrochlore structure were newly found.
5)In a course of study on wide gap p-type conducting oxides some S^0-S^2 mixed valence phases were found. These include Pb^<2+>-Pb^<4+>, Bi^<3+>-Bi^<5+> and Tl^+-Tl^<3+> mixed valence states.
|
