Minority electron unipolar photodetectors based on type II InAs/GaSb/AlSb superlattices for very long wavelength infrared detection

Abstract

We present a hybrid photodetector design that inherits the advantages of traditional photoconductive and photovoltaic devices. The structure consists of a barrier layer blocking the transport of majority holes in a p-type semiconductor, resulting in an electrical transport due to minority carriers with low current density. By using the M-structure superlattice as a barrier region, the band alignments can be experimentally controlled, allowing for the efficient extraction of the photosignal with less than 50 mV bias. At 77 K, a 14 μm cutoff detector exhibits a dark current 3.3 mA/cm2, a photoresponsivity of 1.4 A/W, and the associated shot noise detectivity of 4×1010 Jones.

Epitaxial growth of GaSb and InAs fins on 300 mm Si (001) by aspect ratio trapping

“…The wide range of energy gaps, as well as the unique band offsets between combinations of these materials and their alloys, provide enormous flexibility in designing novel electronic and optical devices [1][2][3]. In particular, GaSb/InAs broken gap heterojunction Tunnel Field-Effect Transistors (TFET) with record high-ON current have recently been demonstrated [4].…”

Mid-Wavelength Infrared nBn for HOT Detectors

“…The bandgap difference between the superlattice and M-structure falls in the valence band, creating a valence-band barrier for the majority holes in a p-type semiconductor. 19 In the case of the nBp structure, the p-n junction can be located at the interface between the heavily doped p-type material and the lower-doped barrier, or within the lower-doped barrier itself. 20 However, a key feature of the devices is the pair of complementary barriers, namely an electron barrier and a hole barrier, formed at different depths in the growth sequence.…”

Design and Development of Two-Dimensional Strained Layer Superlattice (SLS) Detector Arrays for IR Applications

“…In addition, type II SLS detectors based on the 6.1 Å family of materials can be passively cooled, thus reducing the cryocooler burden, and these take advantage of the relatively large installed III-V material manufacturing base [18]. These properties have enabled the fabrication of large format IR FPAs based on type II SLS suitable for high-resolution thermal imaging applications including space-borne surveillance systems, low-background night vision, and missile detection [19][20][21][22][23][24][25][26].…”

“…These include gradedgap W- [19], M- [20], and N-structures [32]; buried junction nBn [21], pBp [22], and pBn [33] designs; and complementary barrier infrared detector (CBIRD) [23] and pBiBn [24] architectures. These device implementations are the result of exploitation of the material, electrical, and optical properties in type II SL materials for optimization of detector performance, which can benefit and advance a diverse array of applications.…”