Reduced graphene oxide film based highly responsive infrared detector

Abstract

Due to the unique optical properties, graphene can effectively be used for the detection of infrared light. In this regard, reduced graphene oxide (RGO) has drawn considerable attention in scientific society because of simplicity of preparation and tunable properties. Here, we report the synthesis of RGO by solvothermal reduction of graphene oxide (GO) in ethanol and the detection of infrared light (1064 and 1550 nm) with metal-RGO-metal configuration. We have observed that photocurrent, responsivity as well as the external quantum efficiency increase with C/O ratio. The responsivity value in near-infrared region can be as high as 1.34 A.W-1 and the external quantum efficiency is more than 100%. Response times of these devices are in the order of few seconds. Overall, the responsivity of our device is found to be better than many of the already reported values where graphene or reduced graphene oxide is the only active material. The high value of quantum efficiency is due to strong light absorption and the presence of mid-gap state in RGOs.

Reduced graphene oxide-based broad band photodetector and temperature sensor: effect of gas adsorption on optoelectrical properties

“…β depends on complex processes of exciton generation, trapping, and recombination , Kind et al, 2002. β is 0.89, 0.99, 0.85 and 0.97 for 1550, 1064, 632 and 325 nm wavelength respectively.…”

“…where h is Plank constant 6.626 × 10 -34 J.s., C is light speed 3×10 8 m.s -1 , q is electronic charge (1.6×10 -19 coulomb) and λ is the wavelength of incident radiation (Khan et al, 2017b, Xia et al, 2009, Afzali et al, 2014. Responsivity and EQE of the device with other reported data at different incident electromagnetic radiation have been listed in table 1.…”

“…Mostly graphene based photodetectors exhibit a responsivity in few ten of mA.W -1 due to fast recombination of photogenerated carriers. Photodetection properties of rGO depend on C/O ratio, structural and impurity defects (Khan et al, 2017b). While increased reduction increases absorption in rGO (Li et al, 2008), defects in rGO can trap or scatter photogenerated carriers which can lead to longer life time of electrons and holes (Gowda et al, 2014).…”

Defect-Mediated Transport in Self-Powered, Broadband, and Ultrafast Photoresponse of a MoS2/AlN/Si-Based Photodetector

“…From the last few decades, substantial research is being done in the field of photodetectors which has led to immense improvements in their performance such as very high responsivities, ultrafast response, and photodetection in a broad range of wavelengths. − Therefore, photodetectors find their applications in a wide variety of fields ranging from day-to-day consumer electronics to more advanced and complex applications, such as industrial and environmental monitoring, flame detection, space communication systems, optical communication, missile technology, proximity sensors, and so forth. ,− Typically, these photodetectors require an externally applied bias as the driving force for efficient separation of the photogenerated electron–hole pairs. ,, Consequently, for systems containing a large number of sensors, energy supply becomes one of the major challenges in the current energy scenario. In regard to the global energy crisis, lots of efforts are being made in the fields of photovoltaics, supercapacitors, thermoelectrics, and self-powered nanodevices. − Self-powered photodetectors, which generate a self-sufficient potential for effective separation of the photogenerated charge carriers, have recently attracted considerable attention because of their numerous advantages. − …”

Large bandgap reduced graphene oxide (rGO) based n-p + heterojunction photodetector with improved NIR performance

“…The reduction of graphene oxide (GO) restores the sp 2 carbon network facilitating controllable bandgap and conducting pathways through C/O ratio manipulation where hybridizations between p-orbitals of oxygen atoms and the frontier orbital of carbon atoms determines the bandgap of rGO. This restoration of sp 2 carbon network in rGO is associated with fast carrier dynamics and enhanced Visible-NIR absorption through conducting π-conjugated carbon network and structural defect driven disordered mid-band states [14,16]. Boukhvalov et al have shown a variation in bandgap of GO sheets from 2.8 to 1.8 eV with varying oxygen containing groups (-OH, COOH, C-O, C=O) coverage (75%-50%) on graphene sheets [17].…”