Donor-acceptor pair emission near 0.55 eV in CdGeAs2.

Autor: Bai, Lihua, Giles, N. C., Schunemann, P. G., Pollak, T. M., Nagashio, K., Feigelson, R. S.
Předmět:
Zdroj: Journal of Applied Physics; 5/1/2004, Vol. 95 Issue 9, p4840-4844, 5p, 1 Diagram, 6 Graphs
Abstrakt: A photoluminescence (PL) study has been performed from 5 to 200 K on a series of p-type bulk CdGeAs2 single crystals. Within our large set of samples, the peak position of an emission band at 5 K was observed to vary from about 0.54 to 0.58 eV when using 1064 nm excitation with a power density of 2.5 W/cm2. The variations of the PL peak position with excitation power and sample temperature have been measured and are consistent with donor-acceptor pair (DAP) recombination in the presence of potential fluctuations. We find that the position of the DAP emission in a particular crystal depends on the hole carrier concentration and the level of compensation. Thermal quenching activation energies of 14 and 120 meV are determined for the donor and acceptor states, respectively. The acceptor defect involved in this radiative recombination is the primary center responsible for the commonly observed room-temperature absorption band at 5.5 μm in p-type CdGeAs2 crystals. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]
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