Defect distribution and metastability in chalcopyrite semiconductors

Conference · Tue Dec 31 00:00:00 EST 1996

OSTI ID:417687

Walter, T; Herberholz, R; Mueller, C; Schock, H W ^[1]

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1. Univ. Stuttgart (Germany). Inst. fuer Physikalische Elektronik

Deep levels in chalcopyrite based heterojunctions are investigated by capacitance techniques. A method is presented which allows the determination of defect distributions from admittance measurements. For CuInSe{sub 2} a defect level at 280 meV above the valence band with an attempt to escape frequency of about 10{sup 11} s{sup {minus}1} is detected. A characteristic defect structure consisting of a shallow defect level and a broad deep structure is observed for Cu(In,Ga)Se{sub 2}. The depth of the shallow defect level and a broad deep structure is observed for Cu(In,Ga)Se{sub 2}. The depth of the shallow defect is affected by annealing treatments which are necessary to achieve the optimum performance of the devices. CuInS{sub 2} grown under an excess of CuS exhibits a high density of shallow defects whereas for Cu-poor CuInS{sub 2} defects close to midgap position with a large capture cross section are observed. These defects are metastable with respect to current injection and illumination relaxing to the equilibrium state around room temperature. The increase of the defect density after illumination results in a reduced bucking current, CV measurements can be interpreted in terms of a high density of deep states.

• OSTI ID: 417687
• Report Number(s): CONF-960401-; ISBN 1-55899-329-0; TRN: IM9705%%60
• Resource Relation: Conference: Spring meeting of the Materials Research Society (MRS), San Francisco, CA (United States), 8-12 Apr 1996; Other Information: PBD: 1996; Related Information: Is Part Of Thin films for photovoltaic and related device applications; Ginley, D. [ed.] [National Renewable Energy Lab., Golden, CO (United States)]; Catalano, A. [ed.] [Technology Assessment Group, Boulder, CO (United States)]; Schock, H.W. [ed.] [Univ. Stuttgart (Germany)]; Eberspacher, C. [ed.] [Unisun, Newbury Park, CA (United States)]; Peterson, T.M. [ed.] [Electric Power Research Inst., Palo Alto, CA (United States)]; Wada, Takahiro [ed.] [Matsushita Electric Industries Co., Ltd., Kyoto (Japan)]; PB: 621 p.; Materials Research Society symposium proceedings, Volume 426
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
14 SOLAR ENERGY
COPPER SELENIDES
CRYSTAL DEFECTS
ELECTRICAL PROPERTIES
INDIUM SELENIDES
GALLIUM SELENIDES
COPPER SULFIDES
INDIUM SULFIDES
SOLAR CELLS
SEMICONDUCTOR MATERIALS
SUBSTRATES
MOLYBDENUM
GLASS
CADMIUM SULFIDES
ZINC OXIDES
CAPACITANCE
CHARGE CARRIERS
BAND THEORY
ANNEALING
ELECTRIC POTENTIAL
ENERGY LEVELS