Transport studies of MBE-grown InAs/GaSb superlattices

Abstract

We report on the results of transport studies of MBE-grown InAs/GaSb superlattices. We demonstrate that the in-plane mobility is limited by interface roughness scattering by showing that, as a function of InAs layer width L, the in-plane mobility behaves as μ ∝ L5.3, which closely follows the classic sixth power dependence expected from theory for interface-roughness-limited mobility. Fits to the mobility data indicate that, for one monolayer surface roughness, the roughness correlation length is about 35 Å. Next, we show that the in-plane carrier mobility in InAs/GaSb superlattices is inversely proportional to carrier density in n- and p-type samples, the result of screened interface roughness scattering.

Mobility Enhancement in Square Quantum Wells: Symmetric Modulation of the Envelop Wave Function

“…At last, for 2DEG in the GaSb/InAs/GaSb square QW, the 10 K mobility was reported in Ref. [27]. There, the used well widths (in units ofÅ) and electron densities (in units of 10 12 cm −2 ) were as follows: (L, p s ) = (41.1, 0.9), (53.6, 1.2), (62.3, 1.6), (72.7, 1.5).…”

“…It should be mentioned that the mobility of a two-dimensional electron gas (2DEG) in 2S doped square QWs was observed in Refs. [18] and [27] for the case where the well width and the sheet electron density were both varied. For 2DEG in the Al 0.3 Ga 0.7 As/GaAs/Al 0.3 Ga 0.7 As QW, the 4.2 K mobility was reported in Ref.…”

“…For this QW of a small misfit = 0.006, SR scattering was indicated to dominate the electron transport. [27,31] The numerical result for 2DEG mobility is displayed in Fig. 2b for a roughness profile of ∆ = 3.2Å, Λ = 15Å, where the data and the flat-band mobility are also shown.…”

“…The solid and empty circles, and empty squares refer to the mobility in the bent-band and flat-band models, and the 10 K experimental data (Ref. [27]), respectively. The lines are a guide for the eyes (b).…”

Contribution of Series Resistance in Modelling of High-Temperature Type II Superlattice p-i-n Photodiodes

“…The function f (b) is a complicated expression involving a trap level and an applied voltage [2]. The values of parameters used in a device modelling are taken from published literature [19][20][21] and are gathered in Table 1 [16]. The description of other mechanisms, essential in high reverse bias voltage condition and detailed discussion of fitting procedure (including simple method of avoiding difficulties connected with the influence of series resistance), can be found in [16].…”