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This content will become publicly available on January 14, 2019

Title: Excitation-dependent carrier lifetime and diffusion length in bulk CdTe determined by time-resolved optical pump-probe techniques

We applied time-resolved pump-probe spectroscopy based on free carrier absorption and light diffraction on a transient grating for direct measurements of the carrier lifetime and diffusion coefficient D in high-resistivity single crystal CdTe (codoped with In and Er). The bulk carrier lifetime t decreased from 670 +/-50 ns to 60 +/- 10 ns with increase of excess carrier density N from 10 16 to 5 x 10 18cm -3 due to the excitation-dependent radiative recombination rate. In this N range, the carrier diffusion length dropped from 14 um to 6 um due to lifetime decrease. Modeling of in-depth (axial) and in-plane (lateral) carrier diffusion provided the value of surface recombination velocity S = 6 x 10 5 cm/s for the untreated surface. At even higher excitations, in the 10 19-3 x 10 20 cm -3 density range, D increase from 5 to 20 cm^2/s due to carrier degeneracy was observed.
Authors:
ORCiD logo [1] ; ORCiD logo [1] ;  [1] ; ORCiD logo [2] ; ORCiD logo [3] ;  [3] ;  [1]
  1. Vilnius Univ. (Lithuania)
  2. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  3. Washington State Univ., Pullman, WA (United States)
Publication Date:
Report Number(s):
NREL/JA-5900-70419
Journal ID: ISSN 0021-8979; TRN: US1801345
Grant/Contract Number:
AC36-08GO28308; AC36-08-GO28308
Type:
Accepted Manuscript
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 123; Journal Issue: 2; Journal ID: ISSN 0021-8979
Publisher:
American Institute of Physics (AIP)
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; semiconductors; pump probe experiments; optical properties; electrical properties; light defraction
OSTI Identifier:
1419412
Alternate Identifier(s):
OSTI ID: 1416650