Influence of Bi on dielectric properties of GaAs_1−xBi_x alloys

Abstract

Pure GaAs and GaAs 1−x Bi x alloys with different Bi ratios (1 %, 2.5 %, 3.5 %) fitted with silver contacts were measured with a dielectric spectroscopy device. Dielectric characterization was performed at room temperature in the frequency range of 0.1 Hz to 1 MHz. GaAs exhibits three relaxation regions corresponding to space-charge, dipolar and ionic polarizations in sequence with increasing frequency while GaAs 1−x Bi x samples show only a broad dipolar polarization in the same frequency range. This result proves the filling of the lattice with Bi through making a new bonding reducing the influence of ionic polarization. This finding supports the previous results concerning optical properties of GaAs 1−x Bi x , presented in the literature.

Power loss mechanisms in n-type modulation-doped AlGaAs/GaAsBi quantum well heterostructures

“…The parameters for GaAs are taken from [23,24]. and the GaAsBi parameters are taken from [25][26][27][28]. The parameters determined from this study are designated as (Exp.).…”

“…The second subband parameters for TNR00 and TNBi04B are given in parenthesis. [23,27] ρ (10 3 kg m −3 ) 5.32 5.44 Sound velocity [23,27] v S (10 3 m s −1 ) 4.79 4.75 Electromechanical coupling constant [23,27] K 2 av 0.025 0.045 Dielectric constant [25,26,28] ε (ε 0 ) 12.9 11.3 Elastic constants [23,27] C 11 (10 11 dyn cm −2 ) 12.21 7.3 Elastic constants [23,27] C 12 (10 11 dyn cm −2 ) 5.66 3.27 Elastic constants [23,27] C 44 (10 11 dyn cm −2 ) 6 3.6 Piezoelectric stress constant [24] e 14 (C m −2 ) −0.16 −0.16 we do not discuss lattice temperature-dependent results here. The obtained parameters (2D carrier density, electron effective mass, Fermi level, transport mobility) from analysis of the temperature dependence of the magnitude of the SdH oscillations are shown in table 3.…”

A quantitative analysis of electronic transport in n- and p-type modulation-doped GaAsBi/AlGaAs quantum well structures

“…The material parameters at ∼4.2 K used in scattering calculations. GaAs-related parameters are taken from [34] and GaAsBi-related parameters are taken from [35][36][37][38]. Some parameters are determined from the present study and ascribed as (exp.)…”

“…in table. The second subband parameters for Bi-free sample (TNR00) and Bi-containing sample annealed at 350 [14] Ξ (eV) 9.5 (7) 7.3 0.5 4 (4.2) Crystal density [34,37] ρ (10 3 kg m −3 ) 5.32 5.44 Sound velocity [34,37] v L (10 3 m s −1 ) 4.79 4.75 Electromechanical coupling constant [34,37] K 2 av 0.025 0.045 Dielectric constant [36,38] ε (ε 0 ) 12.9 11.3 Elastic constants [34,37] C 11 (10 11 dyn cm −2 ) 12.21 7.3 Elastic constants [34,37] C 12 (10 11 dyn cm −2 ) 5.66 3.27 Elastic constants [34,37] C 44 (10 11 dyn cm −2 ) 6 3.6 Piezoelectric stress constant [39] e 14 (C m −2 ) −0.16 −0.16…”