Fig. 5
From: Interface-mediated hygroelectric generator with an output voltage approaching 1.5 volts
Mechanism for the hygroelectric generator. a Theoretical model for the proposed working principle of HEG (Ag/GO-grGO/Au) in which the Au electrode contacts with graphene oxide (GO) side of heterogeneous graphene oxide (h-GO) while Ag electrode contacts with gradient reduced graphene oxide (grGO) side of h-GO. The h-GO is composed of grGO and GO with a thickness of d1 and d2, respectively. Q1, Q2, and Q3 represents the induced positively charge quantity at Au/grGO, GO/grGO, and GO/Ag interfaces, respectively. The built-in electric field at grGO, GO and space charge zone is represented by E1, E2, and Es, respectively. b, c Electrostatic force microscopy (EFM) images of graphene oxide (b) and in situ laser-induced reduced graphene oxide (c) sheets at low relative humidity. The color bar represents the surface potential variation. Scale bars: 1 μm
