Temperature-dependent photoluminescence of ZnO layers grown on 6H-SiC substrates

Abstract

Temperature-dependent photoluminescence (PL) of ZnO layers grown on 6H-SiC substrates has been described. The PL spectra were dominated by free exciton (FX) emission throughout the whole temperature range, which reflects shallow nonradiative centers in high crystalline ZnO layers. The temperature-dependent exciton peak energy as well as intensity quenching due to overlapping of FX and D0X (donor-bound exciton) bands has been addressed with an inclusion of donor-bound exciton-like defects. The D0X linewidth of ∼8 meV exhibited the thermal activation energy of ∼16 meV, closely consistent with the exciton-defect binding energy. This particular bound-exciton peak suggests that it dissociates into a FX and a neutral-donor-bound-like defects pair complex with the increase of temperature.

Synthesis and photoluminescence of Sb-induced ZnO nanowires along with islands attached

“…The spectra are shifted in the vertical direction for clarity. dominated emissions at 3.354 eV, 3.324 eV, and 3.259 eV, which are identified as neutral-donor-bound exciton (D 0 X) [19][20][21], neutral-acceptor-bound exciton (A 0 X) [22], and donor-acceptor pair (DAP) [23,24] transitions, respectively. With an increase of the temperature, the DAP emission at 3.259 eV decreases and disappears at temperature above 50 K [23,24].…”

ZnO QDs Deposited on Si by Sol-Gel Method: Role of Annealing Temperature on Structural and Optical Properties

“…Figure 5 show that the PL spectra of the ZnO QDs show some dependence on the annealing temperature over the range of 425-500 °C. The peak at 368 nm (3.37eV) is characteristic of neutral-donor-bound-exciton (D0X) emission (Zhanget al, 2004;Ashrafi et al, 2004).The appearance of a weak shoulder at ~2.89 eV (violet region) is attributed to radiative recombination from intrinsic defects in the ZnO dots. Quantum confinement effects are not observed in the PL spectra because the size of the QDs is considerably larger than the exciton Bohr radius of ZnO (2.34 nm) (Wang et al, 2011).…”

Interaction Scheme and Temperature Behavior of Energy Transfer in a Light‐Emitting Inorganic‐Organic Composite System

“…Upon increasing temperature, the emission intensity is quenched by thermally activated nonradiative recombination channels, characterized by a rate: t NR ¼ t 0 exp(E a /kT), where E a stands for the process activation energy. [32] Under steady state, the intensity quenching can be consequently described by the expression:…”