Influence of defect density states on NO2 gas sensing performance of Na: ZnO thin films

Impact of oxygen vacancies on enhanced NO2 gas sensing performance of lithium doped Co:ZnO thin films

“…The difference in binding energy between the Zn 2p 3/2 (1021.02 eV) and Zn 2p 1/2 (1044.02 eV) peaks in the Zn 2p spectra, was found to be 23.05 eV, which corresponds to Zn 2+ in ZnO as shown in figure 4(b). Previously, we reported that pure ZnO (CL-1) has only 16% oxygen vacancies [29]. As seen in the O 1s spectrum of CL-3 sample, there is a peak at 530.4 eV (O L = 44.9%) due to the Zn, Co, and Li oxide bonds in the lattice and another peak at 531.8 eV (O V = 55.1%) due to the oxygen in the ZnO matrix, Co 3+ needs more oxygen, figure 4(e) [32,33].…”