Two-dimensional transition metal dichalcogenides such as molybdenum disulfide (MoS2) have attracted great attention due to their unique optical, electrical and chemical properties. MoS2 quantum dots (QDs) exhibit strong quantum confinement, high surface area and notable active edge sites compared to their bulk. In this work, MoS2 QDs were attached on the surface of ZnO nanorods (NRs) grown on interdigitated ITO substrates and then used as photodetector. MoS2 QDs were synthesized by a new ultrafast way pulsed laser ablation (PLA) in liquid method and then spincoated on the surface of ZnO NRs. The pristine ZnO and ZnO/MoS2 QDs photodetector were investigated under UV and visible light (325 nm, 505 nm and 635 nm) with the bias voltage -5 V to 5 V. The results show that the decoration of ZnO NRs by MoS2 QDs could enhance the sensitivity, responsivity and detectivity under UV irradiation. This may due to the decrease of dark current as the result of passivation of surface defects of ZnO NRs by MoS2 QDs.
Zinc oxide (ZnO) has attracted considerable attention because of its potential applications in optoelectronic devices. Many scientists have reported on the preparation of ZnO based photodetectors in metal-semiconductor-metal (MSM) structures where expensive noble metals are used as electrodes. Here, we propose the preparation of full metal-oxide photoconductors by using indium tin oxide (ITO) as the electrodes and ZnO thin films as sensing materials. ZnO thin films were prepared by employing a simple ultrasonic spray pyrolysis (USP) technique with a commercial ultrasonic nebulizer (1.7 MHz). In this work, we developed a high performance ZnO based photodetector on interdigitated ITO with a simple and low-cost USP method. The I-V characteristic shows that ZnO thin film works in a photoconductive mode and has better performance as a UV (325 nm) detector than other wavelengths (505, 625 and 810 nm). As a UV detector, the devices exhibit high sensitivity (1255.51%), high responsivity (22.6 x 103 A/W), high detectivity (1.49 x 1014 Jones), good stability, a fast response time of 0.87 s and a relatively slow recovery time of 34.8 s. This high performance may be related to the large crystallite size that facilitates higher electron mobility.
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