Hydrogen-doped In{sub 2}O{sub 3} transparent conducting oxide films prepared by solid-phase crystallization method

Journal Article · Mon Feb 15 00:00:00 EST 2010 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3284960· OSTI ID:21476124

Koida, Takashi; Kondo, Michio ^[1]; Tsutsumi, Koichi; Sakaguchi, Akio; Suzuki, Michio ^[2]; Fujiwara, Hiroyuki ^[3]

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1. Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology (AIST), Central 2, Umezono 1-1-1, Tsukuba, Ibaraki 305-8568 (Japan)
2. J. A. Woolam Japan Corporation, Fuji 2F, 5-22-9, Ogikubo, Suginami, Tokyo 167-0051 (Japan)
3. Center for Innovative Photovoltaic Center, Gifu University, 1-1, Yanagito, Gifu 501-1193 (Japan)

We have characterized amorphous to crystalline transformation of hydrogen (H)-doped In{sub 2}O{sub 3} (In{sub 2}O{sub 3}:H) films by transmission electron microscopy, thermal desorption spectroscopy, spectroscopic ellipsometry, and Hall measurements. The In{sub 2}O{sub 3}:H films that show a mixed-phase structure embedded with small density of crystalline grains in a large volume fraction of amorphous phase have been fabricated at room temperature by the sputtering of an In{sub 2}O{sub 3} ceramic target with introduction of H{sub 2}O vapor, and the films have been postannealed in vacuum to crystallize the amorphous phase. With increasing annealing temperature up to 200 deg. C, the film shows a large increase in Hall mobility ({mu}{sub Hall}) from 42 to 110 cm{sup 2}/V s and a decrease in carrier density (N{sub Hall}) from 4.6x10{sup 20} to 2.1x10{sup 20} cm{sup -3} with slight decrease in resistivity. The change in {mu}{sub Hall} and N{sub Hall} with annealing temperature is strongly correlated with the volume fractions of the amorphous and crystalline phases in the films. Analyses of dielectric functions of the films using the Drude model revealed that the high electron mobility in the crystallized films is attributed mainly to longer relaxation time rather than smaller effective mass, as compared with as-deposited films. Temperature-dependent Hall analysis, relationship between N{sub Hall} and {mu}{sub Hall}, and comparison between {mu}{sub Hall} and optical mobility showed that (i) scattering processes inside amorphous and/or crystalline matrices limit the mobility, (ii) doubly charged ionized impurity scattering is reduced by crystallization, and (iii) phonon scattering becomes dominant after crystallization in the In{sub 2}O{sub 3}:H films. The above results suggest that H-doping reduces carrier scattering in the crystallized In{sub 2}O{sub 3}:H and structural rearrangements during crystallization eliminate oxygen deficiency and generate H{sup +} that acts as a singly charged donor. In this article, we discuss the transport properties with the variation in microscopic and chemical structures in the In{sub 2}O{sub 3}:H films.

• OSTI ID: 21476124
• Journal Information: Journal of Applied Physics, Vol. 107, Issue 3; Other Information: DOI: 10.1063/1.3284960; (c) 2010 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AMORPHOUS STATE
CARRIER DENSITY
CERAMICS
CRYSTALLIZATION
CRYSTALS
DIELECTRIC MATERIALS
DOPED MATERIALS
EFFECTIVE MASS
ELECTRON MOBILITY
ELLIPSOMETRY
HALL EFFECT
HYDROGEN
INDIUM OXIDES
PHONONS
RELAXATION TIME
SEMICONDUCTOR MATERIALS
TEMPERATURE DEPENDENCE
THIN FILMS
TRANSMISSION ELECTRON MICROSCOPY
VACANCIES
CHALCOGENIDES
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTRON MICROSCOPY
ELEMENTS
FILMS
INDIUM COMPOUNDS
MASS
MATERIALS
MEASURING METHODS
MICROSCOPY
MOBILITY
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PARTICLE MOBILITY
PHASE TRANSFORMATIONS
POINT DEFECTS
QUASI PARTICLES