Extended x-ray absorption fine structure study of arsenic in HgCdTe: p-type doping linked to nonsubstitutional As incorporation in an unknown AsHg{sub 8} structure

Journal Article · Sun Nov 15 00:00:00 EST 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3255989· OSTI ID:21361922

Biquard, X; Alliot, I ^[1]; Ballet, P ^[2]

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1. CEA-INAC, 17 Av. des Martyrs, 38054 Grenoble Cedex 9 (France)
2. CEA-LETI-Minatec, 17 Av. des Martyrs, 38054 Grenoble Cedex 9 (France)

An extended x-ray absorption fine structure (EXAFS) investigation has been carried out on arsenic-doped Hg{sub 70}Cd{sub 30}Te samples. The incorporation of atomic arsenic has been achieved using a nonconventional radio-frequency plasma source in a molecular beam epitaxy reactor. Two samples from the same epitaxial wafer have been studied. One underwent a 400 deg. C activation annealing under Hg pressure, leading to n to p-type conversion. In the commonly admitted scenario, this conversion is associated with the annealing-induced migration of As from a Hg site to a Te site. This study shows that this is not the case. Before annealing, As is found to be involved in noncrystalline structures: 50% inside an As{sub 2}Te{sub 3} chalcogenide glass and 50% inside a new AsHg{sub 8} compact structure. After annealing, the As{sub 2}Te{sub 3} chalcogenide glass disappears, 31% of As occupies Hg sites and 69% incorporates inside this new AsHg{sub 8} compact structure that occupies Te sites. The EXAFS results are in excellent agreement with 77 K Hall-effect measurements. The new AsHg{sub 8} structure is found to have an acceptor behavior. Overall, this study provides an entirely new vision of extrinsic p-type doping of HgCdTe as well as the first experimental evidence of As site transfer induced by annealing.

• OSTI ID: 21361922
• Journal Information: Journal of Applied Physics, Vol. 106, Issue 10; Other Information: DOI: 10.1063/1.3255989; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION
ABSORPTION SPECTROSCOPY
ANNEALING
ARSENIC
ARSENIC TELLURIDES
CADMIUM TELLURIDES
CRYSTAL GROWTH
DOPED MATERIALS
FINE STRUCTURE
HALL EFFECT
MERCURY TELLURIDES
MOLECULAR BEAM EPITAXY
RADIOWAVE RADIATION
SEMICONDUCTOR MATERIALS
THIN FILMS
X-RAY SPECTROSCOPY
ARSENIC COMPOUNDS
CADMIUM COMPOUNDS
CHALCOGENIDES
CRYSTAL GROWTH METHODS
ELECTROMAGNETIC RADIATION
ELEMENTS
EPITAXY
FILMS
HEAT TREATMENTS
MATERIALS
MERCURY COMPOUNDS
RADIATIONS
SEMIMETALS
SORPTION
SPECTROSCOPY
TELLURIDES
TELLURIUM COMPOUNDS