Scanning tunneling microscopic analysis of Cu(In,Ga)Se{sub 2} epitaxial layers
- Department of Materials Science and Engineering, University of Illinois, 1304 W. Green Street, Urbana, Illinois 61801 (United States)
- Department of Electrical and Computer Engineering and Beckman Institute, University of Illinois, 3065 Beckman Institute, 405 N. Matthews St., Urbana, Illinois 61801 (United States)
Scanning tunneling microscopy (STM) measurements have been made on single-crystal epitaxial layers of CuInSe{sub 2} grown on GaAs substrates. Results were obtained for as-grown, air-exposed, and cleaned surfaces; in situ cleaved surfaces; surfaces sputtered and annealed in the STM system; and samples prepared by a light chemical etch. Conventional constant-current topographs, current-voltage curves, and current imaging tunneling spectroscopy (CITS) scans were obtained. Topographic images show that the surfaces appear rough on the atomic scale and often exhibit regular features consistent with a previously proposed surface ad-dimer reconstruction. CITS scans show a spatially varying energy gap consistent with band-edge fluctuations on a scale of a few atomic spacings. Energy variations were observed in both band edges. Although quantitative description of the magnitude of these fluctuations is difficult, the fluctuations on the atomic scale appear much larger than observed by methods such as photoluminescence, which average over larger volumes.
- OSTI ID:
- 21476136
- Journal Information:
- Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 3 Vol. 107; ISSN JAPIAU; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
Similar Records
Observation of double heterostructures for laser diodes using scanning tunneling microscopy and current imaging tunneling spectroscopy in air
Postprocessing Algorithm for Driving Conventional Scanning Tunneling Microscope at Fast Scan Rates
Related Subjects
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
ARSENIC COMPOUNDS
ARSENIDES
CHALCOGENIDES
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
CLEANING
COPPER COMPOUNDS
CRYSTAL GROWTH METHODS
CRYSTALS
DEPOSITION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
EMISSION
ENERGY GAP
EPITAXY
FLUCTUATIONS
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
HEAT TREATMENTS
INDIUM COMPOUNDS
INDIUM SELENIDES
LAYERS
LUMINESCENCE
MATERIALS
MICROSCOPY
MONOCRYSTALS
PHOTOLUMINESCENCE
PHOTON EMISSION
PHYSICAL PROPERTIES
PNICTIDES
SCANNING TUNNELING MICROSCOPY
SELENIDES
SELENIUM COMPOUNDS
SEMICONDUCTOR MATERIALS
SPUTTERING
SUBSTRATES
SURFACE CLEANING
SURFACE COATING
SURFACE FINISHING
SURFACES
TRANSITION ELEMENT COMPOUNDS
VARIATIONS