GaAsSbN/GaAs long wavelength PIN detectors

We report the fabrication of dilute nitride GaAsSbN/GaAs PIN detector with a cut-off wavelength over 1.5 mum. Effect of thermal annealing on the device characteristics is also presented. We found that the thermal treatment increases the acceptor concentration of the GaAsSbN epilayer. The increment leads to the change of conduction type in undoped and Si-doped GaAsSbN and results in low quantum efficiency for the homojunction p-i-n GaAsSbN detector. A heterojunction n-GaAs/i-GaAsSbN/p-GaAsSbN detector was designed to avoid the problem of type conversion. The quantum efficiency of the heterojunction device can reach to 0.13 at 1.1 mum.