One- and two-photon-excited time-resolved photoluminescence investigations of bulk and surface recombination dynamics in ZnSe
1998; American Institute of Physics; Volume: 83; Issue: 9 Linguagem: Inglês
10.1063/1.367268
ISSN1520-8850
AutoresH. Wang, Kam Sing Wong, Bradley A. Foreman, Zheng Yang, George K. Wong,
Tópico(s)Semiconductor Quantum Structures and Devices
ResumoMeasurements of femtosecond time-resolved one- and two-photon-excited photoluminescence of bulk ZnSe enable us to distinguish the surface and bulk contributions to recombination dynamics. A photoluminescence lifetime of several nanoseconds or longer is measured for the bulk. A fast relaxation component with a decay time constant τT of a few tens of picoseconds observed in one-photon-pumped time-resolved spectra is identified as the result of diffusion and rapid surface recombination. A one-dimensional model taking into account surface nonradiative recombination and carrier diffusion is able to describe the observed behavior. The temperature dependence of τT shows good agreement with the theory. At room temperature, a surface recombination velocity S=5.8×105 cm s−1 and a diffusion constant D=10 cm2 s−1 are found using this model.
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