Excitation-Dependent Carrier lifetime and Diffusion Length in Bulk CdTe Determined by Time-Resolved Optical Pump-Probe Techniques. Article No. 025704

Darius Kuciauskas, Patrik Scajev, Saulius Miasojedovas, Algirdas Mekys, Kelvin Lynn, Santosh Swain, Kestutis Jarasiunas

Research output: Contribution to journalArticlepeer-review

38 Scopus Citations

Abstract

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 10^18 cm-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.
Original languageAmerican English
Number of pages9
JournalJournal of Applied Physics
Volume123
Issue number2
DOIs
StatePublished - 2018

NREL Publication Number

  • NREL/JA-5900-70419

Keywords

  • electrical properties
  • light defraction
  • optical properties
  • pump probe experiments
  • semiconductors

Fingerprint

Dive into the research topics of 'Excitation-Dependent Carrier lifetime and Diffusion Length in Bulk CdTe Determined by Time-Resolved Optical Pump-Probe Techniques. Article No. 025704'. Together they form a unique fingerprint.

Cite this