Temperature dependence of bulk luminescence from ZnO

• Published in: Luminescence (Chichester, England) Vol. 33; no. 4; pp. 654 - 659
• Main Authors: Cui, Meima, Zhang, Zili, Wang, Yafang, Finch, Adrian, Townsend, P. D.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.06.2018
• Subjects: Band gap; Data; Emission; Energy gap; Low temperature; Luminescence; Mathematical models; Photonic band gaps; radioluminescence; Temperature; Temperature dependence; Temperature effects; Thermoluminescence; Zinc; Zinc oxide; Zinc oxides; ZnO defects; radioluminescence; temperature dependence; ZnO defects; thermoluminescence
• ISSN: 1522-7235; 1522-7243
• DOI: 10.1002/bio.3460

X‐Ray excited luminescence (radioluminescence, RL) spectra from nominally pure crystalline zinc oxide (ZnO) are reported. The temperature range is from 20 to 673 K. Significant changes of emission band energies and intensities are observed across the temperature range. Photon energies of emission bands linked to the band gap decrease with increasing temperature in RL. This dependence fits the theoretical equations describing the temperature response of the ZnO band gap. Defect related luminescence includes a complex mixture of features at low temperature for RL. Thermoluminescence (TL) signals from 20 to 300 K confirm the presence of an unresolved feature in the RL data. Comments on the possible origin of these bands are summarized. The data underline that it is essential to record the temperature dependence for the luminescence data in order to separate overlapping spectral features.