Demonstration of Planar Type-II Superlattice-Based Photodetectors Using Silicon Ion-Implantation

In this letter, we report the demonstration of a pBn planar mid-wavelength infrared photodetectors based on type-II InAs/InAs(1-x)Sb(x)superlattices, using silicon ion-implantation to isolate the devices. At 77 K the photodetectors exhibited peak responsivity of 0.76 A/W at 3.8 mu m, corresponding to a quantum efficiency, without anti-reflection coating, of 21.5% under an applied bias of +40 mV with a 100% cut-off wavelength of 4.6 mu m. With a dark current density of 5.21 x 10(-6)A/cm(2), under +40 mV applied bias and at 77 K, the photodetector exhibited a specific detectivity of 4.95 x 10(11)cm center dot Hz(1/2)/W.