Subgap time of flight: A spectroscopic study of deep levels in semi-insulating CdTe:Cl

Journal Article · Mon Mar 14 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4943262· OSTI ID:22596888

Pousset, J.; Farella, I.; Gambino, S. ^[1]

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1. Dipartimento di Matematica e Fisica “Ennio De Giorgi,” Università del Salento, Lecce I-73100 (Italy)

We report on a study of deep levels in semi-insulating CdTe:Cl by means of a time-of-flight spectral approach. By varying the wavelength of a pulsed optical source within the CdTe energy gap, transitions to/from localized levels generate free carriers which are analysed through the induced photocurrent transients. Both acceptor-like centers, related to the A-center, and a midgap level, 0.725 eV from the valence band, have been detected. The midgap level is close to the Fermi level and is possibly a recombination center responsible for the compensation mechanism. When the irradiance is varied, either linear or quadratic dependence of the electron and hole collected charge are observed, depending on the dominant optical transitions. The analysis discloses the potentiality of such a novel approach exploitable in the field of photorefractive materials as well as for deep levels spectroscopy.

• OSTI ID: 22596888
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 10; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
A CENTERS
CADMIUM TELLURIDES
CARRIERS
CHROMIUM
ELECTRONS
ENERGY GAP
FERMI LEVEL
HOLES
PHOTOCURRENTS
PULSES
RADIANT FLUX DENSITY
RECOMBINATION
SPECTROSCOPY
TIME-OF-FLIGHT METHOD
TRANSIENTS
VALENCE
WAVELENGTHS