Modeling Photodetection at the Graphene/Ag₂S Interface

Abstract

The synergic combination of nanomaterials with different dimensionalities, such as 2D materials and nanocrystals (NCs), is a promising strategy for application in optoelectronics, such as photodetectors, [1][2][3][4][5][6][7][8] as well as electrochemical devices [9] including memories [10][11][12][13] and sensing, [14,15] leveraging on the different characteristics of their components. The sensitivity of these hybrid systems to both their interface chemistry and physics and external stimuli such as light or electric field allows, on one hand, to develop efficient devices, and on the other hand, to study in depth the interface phenomena related to electron and ion transport.For example, the optical absorption of NCs [5,[16][17][18] can be combined with the excellent electrical conduction of graphene [19,20] in highly responsive hybrid NC/graphene phototransistors. [6,[21][22][23] In these devices, photoexcitation occurs in the NC layer, and the physical separation of electrons and holes (which are transported to the graphene channel) induces a shift of the gate response of the graphene transistor resulting in a large light-induced current modulation. In this configuration, low light absorption in graphene and low electronic mobility in NC films are circumvented. [24] A similar approach can be extended also to other 2D materials. [25,26] The response efficiency and the speed of the device are related to the charge dynamics between the NC and the graphene layer, [8] and several interesting fundamental aspects can be investigated, such as the

Investigation of Glucose Sensing Based on Graphene Conductance

“…[4,5] Graphene or its derivative is coated onto the working electrode surface to improve electron transport between solution and electrode. [6][7][8][9][10] For example, Mao et al fabricated a glucose sensor with Nafion/ GOx/reduced graphene/ZnO nanorods/Au/PET structure, which showed the detection limit was 17.8 μM and the linear range was from 0.1 to 12 mM. [11] Huang et al developed a glucose sensor based on a glassy carbon electrode (GCE) modified by the composite film with the structure of GOx/Nafion/ graphene/Cu nanoparticles.…”