Abstract
The surface engineering of thin films with defined morphology has gained encouragement for offering novel opportunity in the optoelectronic field. Here, we report a novel synthetic approach to grow surface patterened Zn1-xCrxO (0 <= x <= 0.15) thin films via a facile solvothermal approach. The Zn1-xCrxO films are described by X-ray diffraction (XRD), atomic force microscope (AFM) and the near-edge fine structure X-ray absorption (NEXAFS). The optical performance of the Zn1-xCrxO textured films have been inspected by UV-vis. spectrophotometer and the photoluminescence spectroscopy. The incorporation of Cr3+ in the Zn2+ cites of Zn1-xCrxO thin films increased the density of oxygen vacancies and reduced the rate of recombination of photo-induced electron/hole pairs. The light dependence electrical behavior of the Zn1-xCrxO films was explored. The behavior of I-V for the ZnO/Zn0.91Cr0.09O diode exhibited photovoltaic like behavior. The ZnO/Zn0.91Cr0.09O bilayer diode showed a fast response time around 34 ms and decay time of 18 ms under light on and off, respectively. Moreover, ZnO/Zn0.91Cr0.09O bilayer diode exhibited high reproducibility, stability and repeatability under repeated light on and off. A linear increase of the photocurrent against incident light power with sensitivity of 2.42 x 10(5) W/A.cm(2) was achieved. Therefore, one may conclude that the ZnO/Zn0.91Cr0.09O bilayer diode exhibited a high selectivity for blue light, implying the opportunity to use the ZnO/Zn0.91Cr0.09O bilayer as a photodiode.