High Operation Stability and Different Sensing Mechanisms in Graphene Oxide Gel Photodetectors Utilizing a Thin Polymeric Layer

Abstract

We report a significant improvement in the operational stability and photosensitivity of an interdigitated photodetector using a hybrid sensing material based on a reduced graphene oxide gel (femtogel) and poly methyl methacrylate (PMMA). By coating the reduced graphene oxide photodetector with a protective layer of PMMA, a noticeable current stability is achieved, either during a sweep or fixed voltage, compared to an unprotected photodetector. A bolometric-effect sensing mechanism was observed in the unprotected photodetector, whereas the hybrid PMMA/femtogel photodetector displayed a photovoltaic-effect sensing mechanism. This change in the sensing mechanism of the graphene-based device, as a result of encapsulating the sensing area using a polymeric thin layer, is reported for the first time. Moreover, a higher and reliable sensitivity to the low-power illumination source was observed in the hybrid PMMA/femtogel photodetector. This study provides an avenue for engineering the performance and reliability of graphene oxide photodetectors that operate in an ambient environment in order to solve the current bottleneck issue, resulting from the lack of reliability, in commercializing these materials.

Cost‐Effective and Flexible Scalable Fabrication of WO3 UV Photodetectors with Enhanced Performance via Integrated LIG Electrodes

“…These differences can be attributed to the diverse mediums in which WO 3 is dispersed and their particular molecular erections. [ 37 ] The atomic structures of water, acetone, and N , N ‐dimethylformamide (DMF) are depicted in Figure 5d. The illustration demonstrates that water (H 2 O) possesses a curved geometry with three potential atoms for interaction with WO 3 .…”

Enhanced Performance of WO3 Photodetectors Through Hybrid Graphene-Layer Integration

“…Various materials such as MoS 2 , NiO/Ga 2 O 3 , WO 3 , Nb 2 O 5 , WS 2 /TiO 2 , K 2 Nb 8 O 21 , TiO 2 /WO 3 , and graphene (GR) were used as photoactive layers in photodetector devices. − Most recently, some of the hybrid nanostructured materials such as WO 3 nanowires, Bi 2 Se 3 nanobelts, CuInS 2 /ZnS core–shell quantum dots (GQDs), and GR GQDs/TiO 2 /hybrid nanoparticles (HNPs) are explored toward photodetector applications. − Among them, GR was found to be more captivating for optoelectronic and sensor applications. GR was used in ultrafast lasers, solar cells, light-emitting devices to touch screens, transparent electrodes, field-effect transistors, supercapacitors, actuators, organic photovoltaics, etc. , Principally, GR was a single layer of carbon atoms arranged in a honeycomb or hexagonal lattice structure, and it is a gapless semiconductor . GR has a broad-range spectral absorption [visible, infrared, ultraviolet (UV), and terahertz], higher carrier mobility, low dissipation, and a very fast response time .…”