Ionized impurity scattering in periodically δ-doped InP

Electronic scattering in doped finite superlattices

“…21 The quantum mobility Q i of carriers in each miniband and from the Tamm state were obtained from the damping of the SdH amplitudes at 4.2 K, using the procedure described in Ref. 9. The in-plane effective mass m i for the ith electron species-miniband (iϭMB) and Tamm (iϭT) electronswas determined from the temperature dependence of the SdH oscillations for a magnetic field applied perpendicular to the layers, as described in Ref.…”

“…The screening of the scattering potential is treated in the random phase approximation ͑RPA͒, which has been previously applied to multisubband systems with success. 8,9 The electronic scattering and momentum relaxation times are studied as a function of the number of layers in the superlattice, the thickness of the layers, the density of dopants, and the spatial distribution of the doping atoms. To maximize the electronic mobility, the doping atoms are placed in the middle of the potential barriers separating the wells.…”

Anisotropy of the cyclotron mass in superlattices containing two populated minibands

“…In our experiments (B < 17 T), whereas condition (1) is satisfied for electrons belonging to miniband E 1 , it is not satisfied for electrons belonging to miniband E 2 in samples 207 and 200, and only weakly satisfied for sample 206. In addition, an electron in miniband E 2 has a smaller uncertainty in its k-vector than an electron from miniband E 1 , since the former is less frequently scattered [14], which also favours it being Bragg reflected at the minizone boundary, in contrast to electrons from miniband E 1 (the link between uncertainty in k-vector and magnetic breakdown is discussed in [15]). This explains why cyclotron orbits associated with electrons confined to miniband E 2 are always observed in our samples.…”

“…Electrons in miniband E 2 will be distinguishable from those in E 1 only if this energy gap is larger than the energy level broadening. The energy level broadening in single and periodically delta-doped structures has been studied both experimentally [14,20] and theoretically [14,21,22], and for E 2 electrons in periodically delta-doped InP with a carrier density of n S = 5×10 12 cm −2 per period the level width is approximately 10 meV [14]. Our self-consistent calculations show that for the same carrier density the energy gap between E 1 and E 2 minibands is greater than 10 meV only if d is greater than about 50 Å.…”

Effects of thermally activated hole escape mechanism on the optical and electrical properties inp-type Si δ-dopedGaAs(311)Alayers

“…1,2 From a fundamental point of view, ␦-doped layers provide interesting systems for studying the fundamental properties of a two-dimensional carrier gas in the limit of strong coupling with the ionized impurities of the ␦-doped layers. Although several theoretical and experimental works have already been devoted to the study of the fundamental properties of single, [3][4][5] double, 6,7 and multiple ␦-doped (M␦D) layers, [8][9][10][11][12][13][14][15][16][17][18][19][20] in GaAs most of them were related to n-type ␦-doped layers. Little is known about the relevant mechanisms that limit the mobility of the two-dimensional hole gas ͑2DHG͒, as well as which ones control its temperature dependence in p-type M␦D GaAs layers.…”