time response of a resonant tunneling diode based photo- detector (rtd-pd)

In this article, a resonant tunneling diode with alas/gaas double barrier structure using the non-equilibrium green’s function is simulated. a lattice matched ingaas absorption layer is added to the device for light detecting at the wavelength λ=600 nm. the electric field through the device and energy band diagram profile were presented. the photo current of the device and source photocurrent curves versus light intensity are compared. at room temperature, the quantum efficiency of 0.95 was obtained for the device. transient time response of the device was obtained and its dependencies on structural parameters (absorption layer thickness, collector and emitter thickness and doping of the contacts), light intensity, angle of emitted light and voltage bias were simulated and their influences on operation of the device were analyzed. bandwidth of the device was obtained. the simulation results show that when voltage bias increases, fall time decreases and the response of the device is faster. with changing of absorption layer and contacts thicknesses, time response of rtd-pd changes. the variations of doping in contact layers effect on bandwidth. the result show that variations of light intensity and angle of emitted light change transient time response.