Bending effects of ZnO nanorods metal-semiconductor-metal photodetectors on flexible polyimide substrate

The authors report the fabrication and I-V characteristics of ZnO nanorods metal- semiconductor-metal (MSM) photodetectors (PDs) on flexible Polyimide (PI) substrate. From field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) spectrum, ZnO nanorods had a (0002) crystal orientation and a wurtzite hexagonal structure. During the I-V and response measurement, the flexible substrates were measured with (i.e., the radius of curvatures was 0.2 cm) and without bending. From I-V results, the dark current decreased and the UV to visible rejection ratio increased slightly in bending situation. The decreasing tendency of the dark current under bending condition may be attributed to the increase of the Schottky barrier height.