Extraordinary near-band-edge photoluminescence in the highly epitaxial ZnO films deposited by PLD

Effects of Surface States on the Green Luminescence in ZnO

“…After the sample was passivated by a layer of SiO x , however, extraordinary luminescence appeared, as shown in the inset in Figure 3b, indicating that the manually polished sample contains NBE defects. [ 40 ] Because such an extraordinary luminescence was hardly observed for the finely polished samples before and after surface passivation, we come to a conclusion that the GL‐S band of passivated sample under excitation by the incident light with hν ex < E g can be attributed to the ionization of NBE defects, which was substantiated to play an important role in exciting the GL‐S band in our previous work. [ 31 ]…”

“…After the sample was passivated by a layer of SiO x , however, extraordinary luminescence appeared, as shown in the inset in Figure 3b, indicating that the manually polished sample contains NBE defects. [40] Because such an extraordinary luminescence was hardly observed for the finely polished samples before and after surface passivation, we come to a conclusion that the GL-S band of passivated sample under excitation by the incident light with hν ex < E g can be attributed to the ionization of NBE defects, which was substantiated to play an important role in exciting the GL-S band in our previous work. [31] The effects of surface states on the GL band can also be demonstrated using the PL spectra collected from the as-received single-crystal samples at room temperature, as shown in Figure 4a, which were measured using the finely polished samples with different orientations, namely, (0001), (1010), and (1120)-oriented single-crystal samples.…”

Crystallization of ZnO thin films via thermal dissipation annealing method for high-performance UV photodetector with ultrahigh response speed

“…Figure 6a shows the photoluminescence (PL) spectra of the ZnO thin films after various annealing methods and all PL spectra consisted of sharp and broad emissions in the UV and visible regions, respectively. In general, the sharp and strong emission observed in the UV region is referred to as a near-band-edge (NBE) emission and is attributed to the recombination of free excitons, whereas the weak and broad emission observed in the visible region is referred to as a deep-level (DL) emission and is ascribed to defects in the ZnO lattice, such as zinc vacancies, oxygen vacancies, interstitial zinc, and interstitial oxygen [22][23][24][25][26] . As shown in Fig.…”