Photoluminescence characteristics of ZnTe epilayers

Abstract

High quality ZnTe epilayers have been grown on semi-insulating GaAs(100) substrates by hot-wall epitaxy, and the photoluminescence characteristics were investigated. The free exciton binding energy is found to be 12.7 meV and the free exciton reduced mass to be 0.095m0 from the clearly resolved excitonic peaks. From the temperature dependence of the free exciton line, the room temperature energy gap of ZnTe epilayer is found to be 2.278 eV. The longitudinal optical phonon energy from the resonance Raman shift is determined as 26.2 meV. The binding energy of the exciton bound to the neutral acceptor is found to be 4.9 meV. The temperature dependence of the bound exciton peak intensity is explained with a two-step thermal quenching mechanism. Deep level emissions such as donor–acceptor pair emission, Y-band, and oxygen-bound emission are also studied.

Deep emissions of MBE-ZnTe on tilted GaAs substrate

“…4. The temperature dependence of the DAP emissions indicates a two-step thermal quenching process, which is represented by the following equation [6]:…”

“…It is also known that ZnSe epilayers grown on tilted GaAs substrates are high in quality [4,5]. Many authors have reported photoluminescence (PL) of ZnTe grown on GaAs just-cut substrates [6][7][8][9], but there is no report of ZnTe grown on tilted GaAs substrates.…”

Ionization energies of amphoteric-doped Cu2ZnSnS4: Photovoltaic application

“…2-4 showing the VB and the CB edges (e v and e c ) and the acceptor and the donor energy levels (e A and e D ) with respect to Q-Qo can provide important information with respect to the nonradiative recombination. The simplified version of these figures based on linear energy levels with Q(total energy curves quadratic with Q) [42] is shown in Fig. 1.…”

Annealing time on carrier dynamics of ZnTe nanoparticles embedded in a near ultraviolet-transparent glass

“…The PL emission at about 525 nm (2.37 eV) is attributed to deep defects related to zinc vacancies (E V Zn ) [5,23,24] in the ZnTe QDs. The PL emission centered at 630 nm (1.98 eV) is related to oxygen centers (E O ), [5,[25][26][27][28] in both QDs and bulk-like NCs.…”