Influence of alloy stability on the photoluminescence properties of GaAsN/GaAs quantum wells grown by molecular beam epitaxy

Abstract

We have investigated the influence of both the growth rate and the growth temperature on the structural and optical properties of GaAs0.972N0.028/GaAs single quantum wells grown by solid-source molecular beam epitaxy. The results are analyzed in light of the surface phase diagram obtained from in situ reflection high energy electron diffraction. We show that the best quality is achieved at the highest temperature below the onset of alloy decomposition. The use of high growth rates allows one to significantly increase the growth temperature. Our results demonstrate that it is the GaAsN alloy stability which governs the sample properties.

MBE growth and interface formation of compound semiconductor heterostructures for optoelectronics

“…RHEED pattern observed during growth [14]. The observed shift of the (Ga,In)(N,As) PL peak position as well as the broadening, which occurs at high T gr , confirm this observation.…”

Structural and photoluminescence studies of InAsN quantum dots grown on GaAs by MBE

“…Phase decomposition is initiated, as the alloy is thermodynamically unstable. One generally admitted explanation is that rising the temperature enhances the migration of N atoms on the growing surface and induces nitrogen composition fluctuations in GaAsN layers [14]. It is known that, even at low growth temperature, N tends to form clusters in the GaAs matrix [15].…”

“…Therefore the dissolution of the dots while embedding in GaAs accounts for the reduction of the dots size. Uncapped dots dimensions measured by AFM are approximately [40-50] nm  [10][11][12][13][14][15] nm. After embedding in GaAs, similar diameters around 40 nm but much lower heights [1][2] nm, are measured by TEM.…”

Concomitant incorporation of antimony and nitrogen in GaAsSbN lattice-matched to GaAs

“…The RF power of the nitrogen source was kept at 500 W at N 2 flow rate of 0.12 sccm (standard cubic centimeter per minute). The substrate temperature during GaAsSbN growth was kept at 460 1C, which is within the range of temperature where minimum phase segregation of Ga-N was reported [12]. To ensure good structural quality, the V/III ratio was kept at $20 to compensate for arsenic desorption during growth.…”