Abstract
In this study, we prepared a ZnO thin film using the sol-gel spin-coating method on glass substrates. We repeated the synthesis procedure once, twice and four times to obtain the samples. We then investigated the FESEM images, XRD diffractograms, Hall effect and dielectric measurement of the samples. We observed the phase transition from the wurtzite to the zinc blende phase as a result of the number of repetitions. The films exhibited direct band gaps ranging from 3.2 eV to 3.3 eV. This result indicate that the two-times synthesis process has considerably affected the morphology and also improved the crystallinity of the layer. The sample of which the surface was covered with nearly uniform short nanorod grains with an average diameter of ~ 180 nm showed the highest sensitivity to ultraviolet light.
Reference22 articles.
1. E. Monroy, F. Omnès and F. Calle, “Wide-bandgap semiconductor ultraviolet photodetectors,” Semicond. Sci. Technol., vol. 18, no. 4, p. R33, 2003, doi: 10.1088/0268-1242/18/4/201.
2. P. Capper, S. O. Kasap and A. Willoughby, Zinc Oxide Materials for Electronic and Optoelectronic Device Applications. John Wiley & Sons, 2011.
3. P. Hazra and S. Jit, “A p-silicon nanowire/n-ZnO thin film heterojunction diode prepared by thermal evaporation,” J. Semicond., vol. 35, no. 1, p. 014001, 2014, doi: 10.1088/1674-4926/35/1/014001.
4. N. Al-Hardan, A. Jalar, M. A. Hamid, L. K. Keng, N. Ahmed and R. Shamsudin, “A wide-band UV photodiode based on n-ZnO/p-Si heterojunctions,” Sensor Actuat. A–Phys., vol. 207, pp. 61–66, 2014, doi: 10.1016/j.sna.2013.12.024.
5. A. Djurišić, A. M. C. Ng and X. Chen, “ZnO nanostructures for optoelectronics: Material properties and device applications,” Prog. Quantum Electron., vol. 34, no. 4, pp. 191–259, 2010, doi: 10.1016/j.pquantelec.2010.04.001.