Electrical and optical properties of ion beam sputtered ZnO:Al films as a function of film thickness

Journal Article · Thu Jul 01 04:00:00 EDT 1993 · Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States)

DOI:https://doi.org/10.1116/1.578582· OSTI ID:6266780

Qu, Y ^[1]; Gessert, T A; Ramanathan, K; Dhere, R G; Noufi, R; Coutts, T J ^[2]

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1. Colorado School of Mines, Golden, Colorado 80401 (United States)
2. National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

Electrical and optical properties of as-deposited, ion beam sputtered, Al-doped ZnO films have been studied as a function of film thickness and carrier concentration. Hall effect measurements reveal that the bulk electrical resistivity of the film generally decreases with increasing film thickness. Additionally, it is observed that the rate of decreasing resistivity depends on the particular film thickness regime. For thinner films (100--200 nm), the resistivity decreases rapidly with increasing film thickness and is due to increases in both carrier concentration and Hall mobility. However, for thicker films, the resistivity decreases more slowly with increasing film thickness and approaches a nearly constant value at a thickness of 1100 nm. In this thickness regime, the slight decrease in resistivity with increasing film thickness is found to be due to an increase in carrier concentration alone. The above observations suggest the presence of at least two scattering mechanisms. It is speculated that grain boundary and ionized impurity are the most likely mechanisms. These issues, together with observed optical properties of the films, are discussed.

• DOE Contract Number: AC02-83CH10093
• OSTI ID: 6266780
• Journal Information: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States), Journal Name: Journal of Vacuum Science and Technology, A (Vacuum, Surfaces and Films); (United States) Vol. 11:4; ISSN 0734-2101; ISSN JVTAD6
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ALLOYS
ALUMINIUM ADDITIONS
ALUMINIUM ALLOYS
CARRIER DENSITY
CARRIER MOBILITY
CHALCOGENIDES
DIMENSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY-LEVEL DENSITY
FILMS
GRAIN BOUNDARIES
HALL EFFECT
MICROSTRUCTURE
MOBILITY
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SPUTTERING
THICKNESS
THIN FILMS
ZINC COMPOUNDS
ZINC OXIDES