Optical properties of InGaAsN/AlGaAs metal-semi-conductor-metal photodetectors (MSM-PDs) with a modulation-doped heterostructure operating at the wavelength of 1.3 μm have been simulated by a two-dimensional device simulator. Simulation results show that the optimized device structure has a 30-nm-thick cap layer with Nd = 2×1017 cm -3, a 10-nm-thick spacer layer, and 7-μm-wide finger spacing to exhibit the largest photocurrent response and shortest decay response time.
