Green luminescent center in undoped zinc oxide films deposited on silicon substrates

Abstract

The photoluminescence (PL) spectra of the undoped ZnO films deposited on Si substrates by dc reactive sputtering have been studied. There are two emission peaks, centered at 3.18 eV (UV) and 2.38 eV (green). The variation of these peak intensities and that of the I–V properties of the ZnO/Si heterojunctions were investigated at different annealing temperatures and atmospheres. The defect levels in ZnO films were also calculated using the method of full-potential linear muffin-tin orbital. It is concluded that the green emission corresponds to the local level composed by oxide antisite defect OZn rather than oxygen vacancy VO, zinc vacancy VZn, interstitial zinc Zni, and interstitial oxygen Oi.

Depth-resolved cathodoluminescence study of zinc oxide nanorods catalytically grown on p-type 4H-SiC

“…observed a broad, DBE centered at 2.45 eV and assigned it to the oxygen vacancy (Vo) [28]. Using theoretical considerations, the DBE observed at 2.38 eV has been attributed to the oxygen antisite (O Zn ) [29], other candidates are zinc vacancies [30], interstitial zinc (Zn i ) [31], and Cu impurities [31]. In our case, the green emission should be attributed to the point defects mentioned above.…”

Triple excitation with dual emission in paramagnetic ZnO:Er3+ nanocrystals

“…The native point defects responsible for PL emission in ZnO:Er 3+ could be zinc vacancy centre (V Zn2+ ) which act as acceptor centre which lie 0.3 eV (ref. 28 The confocal uorescence map (corresponding to area under black square in the optical image Fig. 2(iv)) and corresponding PL emission spectra under illumination of 980 nm as well as 1550 nm lasers (Fig.…”

Production and recovery of defects in phosphorus-implanted ZnO

“…This implies that some deep level centers prevail even after annealing. As the origin of the deep level luminescence is still under debate, [42][43][44][45] we cannot determine the remaining deep level defects. They are either implantation-induced defects or annealing-induced defects due to defect interaction at high temperatures.…”