High Performance Planar Antimony-Based Superlattice Photodetectors Using Zinc Diffusion Grown by MBE

In this letter, we report a mid-wavelength infrared (MWIR) planar photodetector based on InAs/InAs1-xSbx type-II superlattices (T2SLs) that has a cut-off wavelength of 4.3 mu m at 77 K. The superlattice for the device was grown by molecular beam epitaxy while the planar device structure was achieved by Zinc diffusion process in a metal-organic chemical vapor deposition reactor. At 77 K, the peak responsivity and the corresponding quantum efficiency had the value of 1.42 A/W and 48% respectively at 3.7 mu m under -20 mV for the MWIR planar photodetector. At 77 K, the MWIR planar photodetector exhibits a dark current density of 2.0 x 10(-5) A/cm(2) and the R(0)A value of similar to 3.0 x 10(2) Omega.cm(2) under -20 mV, which yielded a specific detectivity of 4.0 x 10(11) cm.Hz(1/2)/W at 3.7 mu m. At 150 K, the planar device showed a dark current density of 6.4 x 10(-5) A/cm(2) and a quantum efficiency of 49% at similar to 3.7 mu m under -20 mV, which yielded a specific detectivity of 2.0 x 10(11) cm.Hz(1/2)/W.