Optical power dependence of capacitance in uni-traveling-carrier photodetectors

Beyond 110 GHz Uni-Traveling Carrier Photodiodes on an InP-Membrane-on-Silicon Platform

“…For both sizes, an increased reverse bias voltage reduces the junction capacitance, caused by the increased electric field inside the PD that widens the depletion region and decreases the carrier build up in the PD. Additionally, the junction capacitance increases for higher photocurrents for size 10 × 2 µm 2 which follows from accumulation of carriers due to the increased optical power [26]. However, size 3 × 5 µm 2 shows a decrease in junction capacitance for a low photocurrent.…”

Model and data of optically controlled tunable capacitor in silicon single-photon avalanche diode

“…[21] Ma et al analyzed the optical power dependence of capacitance by establishing a differential capacitance model for a single-row carrier photodetector, to optimize the high-speed performance of the detector at different optical powers. [22] Sengouga et al studied the C-V characteristics of two P-type silicon-doped GaAs Schottky diodes and observed that the deviation of the C-V characteristics was related to the deep body defects with non-uniform density. [23] Reference [24] reported the photocapacitance effect in organic heterojunction devices constituting a PN junction, attributing the photocapacitance effect to charge traps.…”