Origin of polychromatic emission and defect distribution within annealed ZnO nanoparticles

Mechanism of visible photon absorption: unveiling of the C3N4–ZnO photoactive interface by means of EPR spectroscopy

“…However, all researchers agree with the fact that the signal at g = 1.96 is derived from the electrons in the conduction band or trapped in the shallow donor levels; in the latter case, the signal seems to be independent of the shallow donor identity 92,93 and the electrons can be modelled in an effective-mass-hydrogenetic-like state. 94 In line with the above mentioned debate, the signal enhancement upon UV irradiation is attributed to the photoexcitation of electrons from the valence band to the conduction band or in…”

Defect-related multicolour emissions in ZnO smoke: from violet, over green to yellow

“…In addition, different transitions matching this energy were calculated by several groups. [87][88][89] Finally, this led to the fact that several defects likely to exist in ZnO were suggested as candidates for this PL band. The attribution of the EPR signal at g=2.002 is, on the other hand, hindered by the fact that it lies very close to the value usually reported for free electrons (g  2.00).…”

Significantly Enhanced Photoluminescence Performance of NixSy(NiS and Ni9S8)/ZnO Nanorods by a Hydrothermal Method

“…The UV emission band is attributed to the recombination of a hole in the valence band and an electron in the conduction band. The visible emission results from the intrinsic defects, including oxygen vacancies (V O ), a zinc vacancy (V Zn ), zinc interstitials (Zn i ), oxygen interstitials (O i ), a zinc antisite (Zn O ), and an oxygen antisite (O Zn ), in ZnO …”

“…Studies of the PL performance of ZnO have yielded the following three results. (1) Adjustments to the preparation conditions of pure ZnO (such as growth atmosphere and annealing temperature) can facilitate the control of intrinsic defects and the study of the PL behavior of ZnO. − Although many researchers have reported results based on (1), the details related to the luminescence mechanism of ZnO remain controversial, especially regarding the source of green emission . (2) Metal-element doping, applying a metal plasmon resonance to adjust the PL behavior of ZnO, is an extremely common method for studying the PL performance of ZnO.…”