High-Speed InSb Photodetectors on GaAs for Mid-IR Applications

Abstract

Cataloged from PDF version of article.We report p-i-n type InSb-based high-speed photodetectors grown on GaAs substrate. Electrical and optical properties of photodetectors with active areas ranging from 7.06 x 10(-6) cm(2) to 2.25 x 10(-4) cm(2) measured at 77 K and room temperature. Detectors had high zero-bias differential resistances, and the differential resistance area product was 4.5 Omega cm(2). At 77 K, spectral measurements yielded high responsivity between 3 and 5 mum with the cutoff wavelength of 5.33 mum. The maximum responsivity for 80-mum diameter detectors was 1.00x10(5) V/W at 4.35 mum while the detectivity was 3.41x10(9) cm Hz(1/2) /W. High-speed measurements were done at room temperature. An optical parametric oscillator was used to generate picosecond full-width at half-maximum pulses at 2.5 mum with the pump at 780 nm. 30-mum diameter photodetectors yielded 3-dB bandwidth of 8.5 GHz at 2.5 V bias

Progress in Infrared Photodetectors Since 2000

“…Further, the material is often combined with various other column IV or VI materials, most commonly arsenic. Attempts have been made to utilize thallium or bismuth to achieve a narrower band gap, but including small amounts of these materials in InSb (<5%) led to great difficulty in material fabrication and dramatically limited device detectivity and responsivity [61,62]. InSb FPAs were capable of pixel counts roughly similar to MCT FPAs at the start of the decade [4].…”

“…Growth on these substrates was accomplished using a variety of means, most commonly MBE growth with the incorporation of buffer layers to reduce the strain at each interface. A number of devices were fabricated on both silicon and GaAs substrates, but these devices uniformly had higher dark current densities, lower responsivities, lower detectivities, and lower maximum operating temperatures than those fabricated on InSb substrates [60,61,63,71]. Other attempts were made at utilizing GaSb substrates, which does have the benefit of being much closer to a lattice match to InSb, with a lattice constant of 6.096 Å and a mismatch of 6%.…”

Investigations on the effect of InSb and InAsSb step-graded buffer layers in InAs0.5Sb0.5 epilayers grown on GaAs (0 0 1)

“…Lee et al [5] first proposed InAsSb superlattice structures for the fabrication of tunable electro-optic devices. Since then, there have been many reports on antimony-based material growth and band gap engineering of the devices for remote sensing of atmospheric gases, molecular spectroscopy and free space communications [4,[6][7][8]. The smallest band gap ($0.1 eV) ternary alloy among the III-V semiconductors has been demonstrated as possible alternate to HgCdTe.…”

Effects of absorption layer characteristic on spectral photoresponse of mid-wavelength InSb photodiodes

“…Applications of these infrared detectors include amongst others, thermal imagers, satellite IR cameras and heat seeking missiles (Shen 1994;Kimukin et al 2004;Rogalski 2003). In order to successfully apply the full potential of the device, it is imperative to fully understand the inner physics mechanism of InSb infrared photovoltaic diode.…”