Piezoelectric properties of zinc blende quantum dots

Abstract

Piezoelectric coefficients of zinc blende (ZB) InN, GaN, and AlN have been estimated from the piezoelectric coefficients of the wurtzite (WZ) system. This procedure is based on a rotation of the first-order piezoelectric tensor of a (001)-oriented ZB structure to a (111)-oriented ZB structure, which is similar to a WZ structure. The derived expressions for the piezoelectric coefficients in a (111)-oriented ZB system are benchmarked against literature coefficients of different WZ materials, showing a very good agreement. To perform the desired opposite operation, a least square fitting procedure was used to find the ZB piezoelectric coefficient e 14 that provides the closest reverse transformation to the known WZ constants. Using e 14 , the piezoelectric potential in a GaN/AlN QD is calculated and compared to a InAs/GaAs QD, revealing a much larger potential in the nitride system, even though the lattice mismatch is much smaller in this system. The result is related to the large piezoelectric coefficient e 14 in ZB nitride materials.

Interplay of morphology, composition, and optical properties of InP-based quantum dots emitting at the 1.55μm telecom wavelength

“…nanostructures has been demonstrated [27], and piezoelectric properties of zinc-blende QDs [28] have been investigated. Continuum k • p models have been used to study the influence of the fields generated by charged defects in the vicinity of QDs [29] as well as the properties of (111)-oriented QDs [30,31].…”

Theory of local electric polarization and its relation to internal strain: Impact on polarization potential and electronic properties of group-III nitrides

“…52 Our value here is in line with more recent studies and analyses which show that a negative value is required both for agreement with experiment and for internal consistency among the different piezoelectric coefficients. 6,[53][54][55] Very recent LDA calculations of second-order polarization of III-nitrides and ZnO by Prodhomme et al 33 show good agreement with our linear coefficients of Table I. The agreement between HSE and LDA highlights the fact that LDA provides reliable values for the electric polarization provided that it also succeeds at predicting reliable band gaps and structural parameters: the largest discrepancies are for the spontaneous polarization of GaN and InN, which are influenced by the discrepancy between HSE and LDA for the calculated value of u 0 .…”

Electron states in a double quantum dot with broken axial symmetry

“…In order to calculate the potential generated by the piezoelectricity, we found the polarization P = P 1 + P 2 up to second order in strain tensor. In the case of zincblende structure growth in the (001) direction, it takes the form 28,37,38 Then, the piezoelectricity-induced charge is calculated from ρ piezo = −∇ • P . Finally, the piezoelectric potential V p is found from the solution of the Poisson-like equation…”