GaAsSb is a low band gap, lattice matched to InP, alternative to GaInAs. Growth and doping using diethyltellurium and carbon tetrachloride were investigated. Hole concentrations up to 1.3×1020 cm−3 have been achieved in as-grown carbon-doped GaAsSb [i.e., no postgrowth annealing was necessary for dopant activation, a key requirement for n-p-n heterojunction bipolar transistor (HBT) structures]. This is a sevenfold improvement over the best carbon-doped InGaAs reported by metalorganic chemical vapor deposition. Hall measurements indicate that GaAsSb’s hole mobility is 55%–60% of GaInAs’s, for a given carrier concentration. InP HBTs with carbon-doped GaAsSb base are demonstrated.

This letter reports the achievement of a high-performance, broad-spectral-band infrared detector with the InAs1−xSbx alloy system using a backside-illuminated heterostructure approach. The basic structure of the detector is obtained with InAs1−xSbx grown by a liquid phase epitaxy technique on a GaSb substrate under lattice-matched or nearly lattice-matched conditions. The measured photoresponse covers the spectral range 1.7–4.2 μm with an external quantum efficiency of 65% without antireflective coating. The typical zero-bias resistance area product is in excess of 109 Ω cm2. The typical leakage current desity is less than 10−9 A/cm2 for 100 mV reverse bias. All parameters were measured at 77 K.

In this paper we report on p-type arsenic doping of CdTe and HgTe/CdTe superlattices by photoassisted and conventional molecular-beam epitaxy (MBE). We also report on some of the problems involved in doping and growing the HgTe/CdTe superlattice system by theoretically examining two key aspects of its growth: (i) growth of CdTe at low temperatures under Cd-stabilized conditions, and (ii) effect of laser excitation on the growing CdTe surface. p-Type arsenic-doped CdTe and HgTe/CdTe superlattice epilayers were grown on (100) CdTe and CdZnTe substrates at low temperatures under cation-stabilized conditions obtained either with excess Cd, or excess Hg fluxes. As-grown arsenic-doped CdTe layers had room temperature carrier concentrations in the 1014–1016 cm−3 range, and hole mobilities of about 35–65 cm2/V s. Low-temperature photoluminescence spectra of arsenic-doped CdTe epilayers grown by photoassisted MBE showed an emission peak at 1.51 eV, which is associated to the AsTe acceptor (arsenic occupying a Te site) with a 92 meV ionization energy. CdTe epilayers grown at low temperatures with photoassisted MBE have superior structural, optical, and electrical properties than those grown by conventional MBE. Arsenic doping of the HgTe/CdTe superlattice structure has resulted in in situ growth of p-type modulation-doped superlattices with enhanced mobilities. Undoped superlattices grown under the same conditions are n-type. These results represent a significant step towards the in situ fabrication of photodiodes and other advanced devices based on HgTe/CdTe doped superlattice structures.

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