Fig. 5
From: Giant piezoresistive effect by optoelectronic coupling in a heterojunction
Formation mechanism of the lateral photovoltage. a Electron–hole pair generation and separation. Under visible light, electron–hole pairs are generated in the depletion region and Si substrate. Then, the generated EHPs in the depletion region are separated by an internal electric field, and the generated holes in the Si substrate tunnel to the 3C-SiC thin film. Schematic band diagrams of the heterojunction at the electrode L area without illumination b and at the electrode R area with illumination c. Under non-uniform illumination, photons are injected into the electrode R area rather than into the electrode L area, resulting in holes generated and injected in this area. Consequently, there is a gradient of the hole concentration in the 3C-SiC layer
