Interface band gap engineering in InAsSb photodiodes

Abstract

The optimization of an InAs0.91Sb0.09 based infrared detector has been performed. The importance of the interfaces between the active region and the contacts in generation recombination phenomena is demonstrated. The two sides of the active region are optimized independently through heterostructure band gap engineering. The use of an Al0.15In0.85As0.91Sb0.09 quaternary makes it possible reach a detectivity of 4.4×109cm√Hz∕W at 290 K and 1.4×1010cm√Hz∕W at 250 K at 3.39μm, offering the perspective of a noncryogenic infrared imaging in the 3–5μm band with quantum detectors.

Modified LPE technique growth and properties of long wavelength InAs0.05Sb0.95 thick film

“…InAs 1−x Sb x has the smallest band gap among all conventional III-V alloys [1][2][3], which has attracted extensive interest for long-wavelength (8-12 m) optoelectronic applications. In recent years, ternary InAs 1−x Sb x has shown its potential usefulness for 8-12 m room-temperature devices [4][5][6]. The InAs x Sb 1−x is also useful for high-speed electron devices because of its very high electron mobility.…”

Dots, QWISPs, and BIRDs

“…A DH detector design, depicted in Fig. 7, can be used to reduce diffusion dark current emanating from the diffusion wings surrounding the absorber layer [27]. The nBn [28] (see Fig.…”

“…In practice, unipolar barriers are not always readily available for the desired infrared absorber material, as both the absorber and barrier materials require (near) lattice matching to available substrates, and the proper band offsets must exist between the absorber and the barrier. Considerable effort and ingenuity may be required to circumvent such difficulties [27].…”

Antimonide superlattice complementary barrier infrared detector (CBIRD)

“…Unipolar barriers have also been used extensively to enhance infrared detector performance, for example by impeding the flow of majority carrier dark current in photoconductors [38]. A DH detector design can be used to reduce diffusion dark current emanating from the diffusion wings surrounding the absorber layer [2]. The nBn [3][4][5] or XBn [6][7][8][9] detector structure uses a unipolar barrier to suppress dark current associated with Shockley-Read-Hall processes without impeding photocurrent flow, as well as to suppress surface leakage current [5].…”

“…The versatility of the antimonides has been manifested in a variety of semiconductor devices. The antimonides have also emerged recently as a highly effective platform for developing of sophisticated heterostructure-based mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) detectors, as exemplified by the high-performance double heterstructure (DH) [2], nBn [3][4][5], XBn [6][7][8][9], and type-II superlattice infrared detectors [10][11][12][13][14][15][16][17][18]. A key enabling design element is the unipolar barrier [18], which is used to implement the barrier infrared detector (BIRD) design for increasing the collection efficiency of photogenerated carriers, and reducing dark current generation without impeding photocurrent flow.…”