Photoabsorptance and electron lifetime measurement in HgCdTe

Autor: J. F. Shanley, O. L. Doyle, J. A. Mroczkowski
Rok vydání: 1985
Předmět:
Zdroj: Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films. 3:259-263
ISSN: 1520-8559
0734-2101
DOI: 10.1116/1.573213
Popis: Photoinduced absorption modulation near the band gap is used for the first time to measure the excess electron lifetime and gap energy in several samples of bulk and LPE Hg0.2Cd0.8Te. The samples were primarily n‐type with carrier concentrations from 3×1013 to 2×1015 cm−3. The fractional transmission change ΔI(E)/I(E) near Eg, due to a nonequilibrium Burstein–Moss shift, is described by a simple theory based on bandfilling, with empirical modifications to include broadening effects in LPE films. Lifetimes are determined by three methods: (1) ΔI/I spectra, (2) high frequency rolloff of the total ΔI signal, and (3) transient analysis of photoconductivity decay. Measured values of 100 to 800 ns are obtained, with excellent agreement between the three independent results for a given sample.
Databáze: OpenAIRE