Mid-Wavelength InAs/InAsSb Superlattice Photodetector With Background Limited Performance Temperature Higher Than 160 K

We report on a mid-wavelength (MW) type II superlattice (T2SL) photodetector using Ga-free InAs/InAsSb SL structure. X-ray diffraction (XRD) measurements indicate that the strained SL material is of very high quality. It is demonstrated that the background limited performance (BLIP) temperature of the detector is above 160 K and the dark current is dominated by the diffusion mechanism when temperature is above 160 K. At 77, 160, and 280 K, the 50% cutoff wavelength of the detector is 4.54, 4.89, and 5.56
$\mu \text{m}$
, respectively. The responsivity at the peak wavelength is 2.13 A/W at 77 K and is 2.16 A/W at 160 K. We also extract the Varshni parameters of the SL structure. The results indicate that the Ga-free SL structure is similar to InAs bulk material in terms of the Varshni parameters.