No abstract

No abstract

In this paper, we have investigated the effect of Mn doping on the electrical properties of ZnO thin films. ZnO thin films with different amounts of Mn concentrations (0, 5, 10 and 15 mol.%) were prepared by spray pyrolysis technique. The crystal structure was examined by X-ray diffraction (XRD) analysis. XRD patterns showed that all the samples were crystallized in wurtzite structure while a decrease in crystallinity and switch in preferential orientations were observed in Mn-doped thin films comparing to undoped ZnO. The element composition of all thin films was detected by energy dispersive X-ray (EDX). The surface morphology of the films was investigated using field emission scanning electron microscope (FESEM) and optical properties were studied using UV-vis spectroscopy. UV-vis study revealed that the band gap blueshifts with the increase in Mn content and [Formula: see text] increases with the increase in Mn concentration. The resistivity and activation energy were measured at room temperature and ranging from 373 K to 573 K. Comparing to undoped ZnO thin film, the resistivity of Mn-doped ZnO films increased because of different parameters such as increasing barrier height energy and reducing the oxygen deficiency.

A simple spray pyrolysis technique has been used to fabricate ZnO/Mn thin films with different Mn concentrations (0, 5, 10 and 15 mol.%) for gas sensing applications. X-ray diffraction (with Cu-Ka radiation) patterns of the samples revealed the formation of single-phase wurtzite structure. The samples were characterized using field-emission scanning electron microscopy and scanning tunneling microscopy. The investigation revealed that the surface of pure ZnO thin film appears rougher and containing bigger grains. The response of the pure and Mn-doped ZnO thin-film gas sensors was checked at different temperatures ranging from 120 up to 200°C, to investigate the optimum sensing efficiency. The gas sensing results have demonstrated that the pure ZnO thin film exhibited higher sensitivity to CO 2 gas at 150°C operating temperature, while the sensitivity reduced with the increase in gas pressure. Although the sensitivity of doped samples was lower than the pure sample, the sensitivity increased with the increase in pressure.

In this study, the structural and electronic properties of armchair graphdiyne nanoribbons, which have different widths are studied using the first principle calculation. The results indicate that all studied AGDYNRs show semiconducting behavior in which the band gap values decrease with the increase of nanoribbons width. The electronic and electrical properties of the graphdiyne sandwiched between two graphene nanoribbons are also investigated. The findings of our study indicate that among 4 investigated n-G-GDY-G-NR structures, the highest current is calculated for n = 3 (3-G-GDY-G-NR), due to phase transition.