Charge carrier scattering channels in graphite bridging its valence and conduction band offer an efficient Auger recombination dynamic to promote low energy charge carriers to higher energy states. It is of importance to answer the question whether a large number of charge carriers can be promoted to higher energy states to enhance the quantum efficiency of photodetectors. Here, we present an experimental demonstration of an effective Auger recombination process in the photo-excited nano-graphite film. The time-resolved hot carrier thermalization was analyzed based on the energy dissipation via the Auger scattering channels. We split the Auger recombination occurrence centered at 0.40 eV energy state into scattering and recombination parts, for characterizing the scattering rate in the conduction band and the recombination rate toward the valence band. The scattering time with respect to the energy state was extracted as 8 ps · eV⁻¹, while the recombination time with respect to the energy state was extracted as 24 ps · eV⁻¹. Our study indicates a 300 fs delay between the hot carrier recombination and generation, leading to a 10⁵ ps⁻¹ · cm⁻³ Auger scattering efficiency. The observed duration for the Auger recombination to generate hot carriers is prolonged for 1 ps, due to the hot carriers energy relaxation bottleneck with optical-phonons in the nano-graphite. The presented analytic expression gives valuable insights into the Auger recombination dynamic to estimate its most efficient energy regime for mid-infrared photodetection.

This work presents a novel InGaAs/InP avalanche photodiode fabricated in the separate absorption, grading, charge, and multiplication configuration operated at non-cryogenic conditions under low-frequency ramp gating. An optimized three stage InP multiplication layer of 1μ m thickness offers extended linear mode operation by reducing the punch-through voltage and indefinitely increasing the avalanche threshold voltage. A large background dark current is observed following steady, and linear multiplication in approximately direct relationship with the ramp gating. For 1310 nm short-wave infrared, normal incidence pulsed illumination at instant-to-peak voltage ratios of (0.11,0.2,0.6,0.89,0.98,0.9), a sort of negative differential resistance is incorporated into the device in a qualitative sense, owing to the illumination induced switching/variations in the intrinsic values of electron and hole avalanche coefficients in the multiplication region. Under fixed illumination, an interesting deduction from the transient photo response is the slow quenching phenomenon prolonging ~120 μ s for all the electrical field establishments in the device. The related measurement scheme paves the way for futuristic ramp-driven InGaAs/InP APDs for detecting SWIR wavelengths under required low power consumption environments.