Growth and characterization of AlGaInAs lattice matched to InP grown by molecular-beam epitaxy

Abstract

We present a complete investigation of crystalline, optical, and electrical properties of molecular-beam-epitaxial-grown AlGaInAs lattice matched to InP covering the whole range of concentrations. Using the two indium cells method, we show very easy control of lattice matching of this quaternary system which can be written as (Al0.48In0.52As)z(Ga0.47In0.53As)1−z. X-ray double diffraction profiles do not depend on the Al concentration and they show sharp diffraction linewidth. The PL full widths at half maximum are comparable to the narrowest reported. Transmission electron microscopy shows excellent crystallinity for z up to 0.60. Room-temperature electron mobility higher than 4000 cm2/V s for z up to 0.40 is comparable to that of InP and is the best result reported up to now for these quaternary alloys. This system is thus quite suitable for microwave and optical devices applications.

A convenient band-gap interpolation technique and an improved band line-up model for InGaAlAs on InP

“…4. The interpolation result is in good agreement with the experimental data measured at 4.2 K [13], 5.5 K [12], and 10 K [11] respectively. The interpolated values matched well and exhibit a maximum deviation of 0.027 eV from the experimental data.…”

“…On the other hand, the dash-dot curve represents the results of those with lower energy values, and it is obtained by fitting the interpolation curve to those of Gaskill et al [24]. The experimental band-gap values in the same figure was obtained from the reports studying the composition-dependent band-gap energy of InGaAlAs [6][7][8][10][11][12][13][14]. As observed in Fig.…”

“…Figure 6 depicts the calculations results adopted from [20] which are compared against the empirical formula [6]. On the other hand, our calculation result, using the same input values in [20], based b From [11,32]: E g = 0.80 + 1.58y…”

“…The existence of non-linear dependence in the band-gap energy to the aluminium content, also known as the bowing effect, of In 1 − x − y Ga x Al y As has been well supported by the experiment [6][7][8] and theoretical [9] results. Contrarily, independent measure-ment results [10][11][12][13][14] showed linear variations of bandgap energy to the aluminium content. To date, there are a range of interpolation techniques available for the determination of In 1 − x − y Ga x Al y As band-gap energy.…”

“…The quaternary value of the other parameters, such as c 11 , c 12 , Δ so , a c , a v , and b may be interpolated by Vergard's law. v. The energy band levels are then calculated by following the ordinary band line-up procedure with (7)- (12) using either the experimental band-gap energy, or the interpolated band-gap energy.…”