Thermal conductivity of AlAs0.07Sb0.93 and Al0.9Ga0.1As0.07Sb0.93 alloys and (AlAs)1/(AlSb)11 digital-alloy superlattices

Abstract

A differential 3 technique is employed to determine the thermal conductivity of the AlAs 0.07 Sb 0.93 ternary alloy, the Al 0.9 Ga 0.1 As 0.07 Sb 0.93 quaternary alloy, and an (AlAs) 1 /(AlSb) 11 digital-alloy superlattice. Between 80 and 300 K, the thermal conductivities for all three samples are relatively insensitive to temperature. The thermal conductivity of the (AlAs) 1 /(AlSb) 11 superlattice is smaller than that of the AlAs 0.07 Sb 0.93 ternary alloy, but much larger than the predictions of a model for phonon transport across the superlattice interfaces.

Lattice thermal conductivity of group-IV and III–V semiconductor alloys

“…Thermal conductivity K vs composition x for ͑Ga, In͒-based IIIϪV ternary alloys: ͑a͒ Ga x In 1−x As and ͑b͒ Ga x In 1−x Sb. The experimental data in ͑a͒ are taken from Abrahams et al 26 and Arasly et al 27 and those in ͑b͒ are from Magomedov et al 28 The open circles represent the experimental data of the end point binary materials listed in Table I 31 The open circles represent the experimental data of the end point binary materials listed in Table I. The solid lines are obtained from Eqs.…”

“…7͑a͒ and 7͑b͒, respectively. The experimental data are taken from Borca-Tasciuc et al 31 The solid lines are calculated from Eqs. ͑1͒ and ͑2͒ with C As-Sb =91 cm K/W.…”

Rethinking phonons: The issue of disorder

“…55 The GK error bars were determined based on the standard deviation of results from independent simulations at a given Indium composition. Here, it should be noted that at 300 K there is a minimal effect from quantum corrections and thus, to reduce computational expense, GK as opposed to GKMA calculations were performed, b Average eigenvector periodicity parameter and fraction of propagating modes vs. Indium composition, c Eigenvector periodicity parameter for different alloy compositions These clear failures [29][30][31][32] of the current theory have prompted our rethinking of phonon transport in general, with a random alloy used here as an example.…”

“…As a result, the VCA still represents the most advanced theoretical understanding of phonon transport in alloys, and this has largely been justified by the instances in the literature, where good agreement between the VCA and experiments has been observed. [22][23][24][25]27,28 Unfortunately there are instances where the VCA fails, [29][30][31][32] even when adjustable parameters are used to fit the data to which it is compared. 30,31 It is also important to note that these failures are not only quantitative, [29][30][31][32] but also qualitative, 29,30,32 particularly with respect to describing TC vs. temperature.…”

“…[22][23][24][25]27,28 Unfortunately there are instances where the VCA fails, [29][30][31][32] even when adjustable parameters are used to fit the data to which it is compared. 30,31 It is also important to note that these failures are not only quantitative, [29][30][31][32] but also qualitative, 29,30,32 particularly with respect to describing TC vs. temperature. This is because some alloys exhibit monotonically increasing TC or seemingly constant TC vs. temperature, 29,30,32 and the VCA will rather inherently always yield the same qualitative temperature dependence as a pure crystal, which consists of a low-temperature peak (dictated by the competition between phonon-phonon scattering and phonon-impurity scattering) followed by monotonically decreasing TC due to anharmonic phonon-phonon scattering.…”