Factors Influencing Photoluminescence and Photocarrier Lifetime in CdSeTe/CdMgTe Double Heterostructures
Swartz, Craig H.
Zaunbrecher, K. N.
LeBlanc, E. G.
Ogedengbe, Olanrewaju S.
Petersen, John E.
Jayathilaka, Pathiraja A. R. D.
Myers, Thomas H.
American Institute of Physics
CdSeTe/CdMgTe double heterostructures were produced with both n-type and unintentionally doped absorber layers. Measurements of the dependence of photoluminescence intensity on excitation intensity were carried out, as well as measurements of time-resolved photoluminescence decay after an excitation pulse. It was found that decay times under very low photon injection conditions are dominated by a non-radiative Shockley-Read-Hall process described using a recombination center with an asymmetric capture cross section, where the cross section for holes is larger than that for electrons. As a result of the asymmetry, the center effectively extends photoluminescence decay by a hole trapping phenomenon. A reduction in electron capture cross section appeared at doping densities over 10 16cm-3. An analysis of the excitation intensity dependence of room temperature photoluminescence revealed a strong relationship with doping concentration. This allows estimates of the carrier concentration to be made through a non-destructive optical method. Iodine was found to be an effective n-type dopant for CdTe, allowing controllable carrier concentrations without an increased rate of non-radiative recombination.
photoluminescence, ohmic contacts, neutron cross section, chemical elements, photocarrier, Physics
Swartz, C. H., Zaunbrecher, K. N., Sohal, S., LeBlanc, E. G., Edirisooriya, M., Ogedengbe, O. S., Petersen, J. E., Jayathilaka, P. A. R. D., Myers, T. H., Holtz, M. W., & Barnes, T. M. (2016). Factors influencing photoluminescence and photocarrier lifetime in CdSeTe/CdMgTe double heterostructures. Journal of Applied Physics, 120(16).