State-of-the-art AlGaAs alloys by antimony doping

Abstract

Historically GaAlAs alloys grown by molecular-beam epitaxy have high deep level concentrations (>1016 cm−3), low luminescent efficiency with broad peaks, and are difficult to dope controllably below mid 1016 cm−3. We report the effect that the low incident antimony molecule fluxes during growth appear to help reduce the density of deep levels below 1014 cm−3, which then allows reproducible doping control in the low 1015 cm−3 range. Exciton-dominated photoluminescence with half widths ∼4.0 meV are now routinely achieved using this technique. Further evidence for the quality improvement of AlGaAs by heavy atom (Sb) doping comes from high 4 K two-dimensional electron gas mobilities for low sheet electron densities, e.g., 1.3×106 cm2/V s for n=2×1011 cm−2. SIMS profiles of antimony content are presented and estimates of incorporated concentrations are given.

Optical properties of AlAs/GaAs quantum wells with antimony as a surfactant by solid source molecular beam epitaxy

“…It is clearly shown that the incorporation of very small amounts of Sb doping greatly improves the interface quality of AlAs/GaAs MOWs. Due to the relatively weaker bond of AlSb than that of AlAs, it may decrease the surface free energy of Al and result in enhanced Al diffusion [4][5][6][7]. Sb at the surface preferentially occupies those more stable sites at the step edges, and by changing the local energy configuration facilitates the descent of Al down the sites [5].…”

“…The surfactant strongly affects surface properties, such as surface energy, surface diffusion and surface morphology [3]. Due to the high Al-As bond strength, which reduces the surface mobility of Al, Sb as a surfactant has successfully been made to reduce the surface free energy, and hence enhance the surface migration of cation Al adatoms and has been used to improve the interfacial and crystalline quality in aluminium-containing material growth [4][5][6][7]. The interface quality plays an important role in the optical and electronic properties of devices such as vertical-cavity surface-emitting lasers (VCSELs) [8], quantum well lasers [9], high electron mobility transistors [10], and resonant tunneling diodes [11].…”

Antimonene: a tuneable post-graphene material for advanced applications in optoelectronics, catalysis, energy and biomedicine

“…With respect to the main applications, antimony compounds can be used in different fields such as flame retardants (Sb 2 O 3 ), catalysis (SbF 5 ), pyrotechnical articles (Sb 2 S 3 + H 2 S) or in electronics (alloyed with Ga and As). 17,24 Related to electronic applications, Sb is mainly used in semiconductor devices such as diodes and infrared detectors. Alloying with Pb or other metals can enhance its hardness and strength.…”

Impact of carrier localization on the photoluminescence characteristics of (Ga,In)(N,As) and (Ga,In)(N,As,Sb) quantum wells

“…IV and V and in particular to the values for ⌬E, which clearly imply a stronger localization for sample 2. 37,38 5, it becomes clear that our simplified model is not able to describe the convex shape of the data observed for sample 1.…”