School of Electronic Science and Applied Physics and Anhui Provincial Key Laboratory of Advanced Functional, Materials and Devices, Hefei University of Technology, Hefei, Anhui 230009, PR China.
Small. 2013 Sep 9;9(17):2872-9. doi: 10.1002/smll.201203188. Epub 2013 Mar 13.
A new Schottky junction ultraviolet photodetector (UVPD) is fabricated by coating a free-standing ZnO nanorod (ZnONR) array with a layer of transparent monolayer graphene (MLG) film. The single-crystalline [0001]-oriented ZnONR array has a length of about 8-11 μm, and a diameter of 100∼600 nm. Finite element method (FEM) simulation results show that this novel nanostructure array/MLG heterojunction can trap UV photons effectively within the ZnONRs. By studying the I-V characteristics in the temperature range of 80-300 K, the barrier heights of the MLG film/ZnONR array Schottky barrier are estimated at different temperatures. Interestingly, the heterojunction diode with typical rectifying characteristics exhibits a high sensitivity to UV light illumination and a quick response of millisecond rise time/fall times with excellent reproducibility, whereas it is weakly sensitive to visible light irradiation. It is also observed that this UV photodetector (PD) is capable of monitoring a fast switching light with a frequency as high as 2250 Hz. The generality of the above results suggest that this MLG film/ZnONR array Schottky junction UVPD will have potential application in future optoelectronic devices.
一种新型肖特基结紫外光电探测器（UVPD）是通过在独立的 ZnO 纳米棒（ZnONR）阵列上涂覆一层透明单层石墨烯（MLG）薄膜制成的。单晶[0001]取向的 ZnONR 阵列的长度约为 8-11μm，直径为 100∼600nm。有限元方法（FEM）模拟结果表明，这种新型纳米结构阵列/MLG 异质结可以有效地在 ZnONRs 内捕获紫外光子。通过在 80-300K 的温度范围内研究 I-V 特性，在不同温度下估计了 MLG 薄膜/ZnONR 阵列肖特基势垒的势垒高度。有趣的是，具有典型整流特性的异质结二极管对紫外光照射具有高灵敏度和毫秒上升/下降时间的快速响应，具有出色的可重复性，而对可见光照射则较弱。还观察到，这种紫外光电探测器（PD）能够监测高达 2250Hz 的快速开关光。上述结果的普遍性表明，这种 MLG 薄膜/ZnONR 阵列肖特基结紫外 PD 将在未来的光电设备中有潜在的应用。
