White-Light Photosensors Based on Ag Nanoparticle-Reduced Graphene Oxide Hybrid Materials

• Published in: Micromachines (Basel) Vol. 9; no. 12; p. 655
• Main Authors: Tu, Wei-Chen, Liu, Xiang-Sheng, Chen, Shih-Lun, Lin, Ming-Yi, Uen, Wu-Yih, Chen, Yu-Cheng, Chao, Yu-Chiang
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 11.12.2018; MDPI
• Subjects: Ag nanoparticles; Electric fields; finite-difference time-domain; Graphene; Light; Morphology; Nanocomposites; Nanoparticles; Optical properties; Optoelectronic devices; Particle size; photosensor; reduced graphene oxide; Room temperature; Silver; solution process; Spectrum analysis; Time domain analysis; White light; photosensor; reduced graphene oxide; solution process; Ag nanoparticles; finite-difference time-domain
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi9120655

The unique and outstanding electrical and optical properties of graphene make it a potential material to be used in the construction of high-performance photosensors. However, the fabrication process of a graphene photosensor is usually complicated and the size of the device also is restricted to micrometer scale. In this work, we report large-area photosensors based on reduced graphene oxide (rGO) implemented with Ag nanoparticles (AgNPs) via a simple and cost-effective method. To further optimize the performance of photosensors, the absorbance and distribution of the electrical field intensity of graphene with AgNPs was simulated using the finite-difference time-domain (FDTD) method through use of the surface plasmon resonance effect. Based on the simulated results, we constructed photosensors using rGO with 60⁻80 nm AgNPs and analyzed the characteristics at room temperature under white-light illumination for outdoor environment applications. The on/off ratio of the photosensor with AgNPs was improved from 1.166 to 9.699 at the bias voltage of -1.5 V, which was compared as a sample without AgNPs. The proposed photosensor affords a new strategy to construct cost-effective and large-area graphene films which raises opportunities in the field of next-generation optoelectronic devices operated in an outdoor environment.