High-Speed Mid-Wave Infrared InAs/InAsSb Superlattice Uni-Traveling Carrier Photodetectors With Different Absorber Doping

In this article, we studied two high-speed mid-wave infrared InAs/InAsSb type-II superlattice (T2SL) uni-traveling carrier (UTC) photodetectors (PDs) with different graded p-doping profiles in the absorber. It is found that the UTC device with higher absorber p-doping (hereafter referred to as Device A) has a larger 3-dB bandwidth than that of the device with lower absorber p-doping (hereafter referred to as Device B). However, Device A shows a higher dark current and lower responsivity performance than Device B. The peak responsivity of Devices A and B is about 0.9 and 1.2 A/W, respectively, under −1 V at room temperature. The performance comparisons of both devices are explored in detail. These results could contribute a further step toward developing high-speed InAs/InAsSb T2SL PDs.