Detailed calculation of the thermoelectric figure of merit in ann-doped SiGe alloy

Tuning phonon properties to enhance the thermoelectric figure of merit

“…[13]; since this determination is fairly involved, we refer those who are interested to Ref. [11], in which it is discussed in detail, and focus on the details of the calculation in the case of superlattices in what follows.…”

“…[11]. The Interface Mixing scattering (IMS) rate τ −1 IMS (q q qs) arises from 'masssmudging' (the formation of dislocations is neglected here, for the superlattice under consideration is well below the critical length for their formation [14]); for this and the anharmonic scattering rate τ −1 AH (q q qs) we use the formulation from Ref.…”

“…[12] (note that the formulation of the anharmonic term in [12] differs slightly from the version used in Ref. [11] to calculate the anharmonic scattering in the alloy).…”

“…We take N D = 9.4 × 10 25 m −3 , the electron effective mass corresponding to the well (i.e. the Si mass; see below), E D = 10 eV (slightly smaller than the value used in References [11] and [15]) and take L B = 0.2 μm as per the alloy [11]. We parameterise P using α = 5.0 and B = 1.0, which corresponds to a good quality interface [12].…”

“…One such method would be a judicious combination of ab inito and semi-empirical approaches, as developed in our group over several years [9,10,11,12]. In this approach we generate phonon eigensolutions for the system of interest from second-order force constants obtained by DFPT, and use them as input for analytically-derived expressions for the relevent contributions to the singlemode relaxation time.…”