Piezoelectric effect in wurtzite GaAs nanowires: Growth, characterization, and electromechanical 3D modeling

Abstract

The piezoelectric effect in wurtzite-type GaAs nanowires was theoretically analyzed using an electromechanical 3D model. The difference between the theoretical and measured piezoelectric strain coefficient is explained by an enhanced pressing force of the contact layer on the nanowire. Simulations show the potential decreasing when nanowires are partly inside in the top metal contact due to a decreasing effective length and pressing force enhancement.

Direct Band Gap AlGaAs Wurtzite Nanowires

“…However, this leads to completely incompatible results both with our experimental data and, in general, with those present in literature. We therefore chose for GaAs the piezoelectric coefficients from ref 53, which are also confirmed by recent experimental works 54 and which are about a quarter of the mean values of the III−N materials parameters, and for AlAs we chose those of ref 55 to our knowledge the only ones attested, which are of an order of magnitude lower.…”

Piezoelectric Current Generation in Wurtzite GaAs Nanowires

“…The piezoelectric characteristics of GaAs NWs with a WZ structure are poorly understood . Recently, a piezoelectric structure based on an array of such NWs with an average PSC of d 33 = 26 pC/N was demonstrated . However, more detailed study of the piezoelectric properties of individual GaAs NWs is still required and is a topical problem.…”

“…The following material parameters were used in the calculations: density ρ = 5.31 g/cm 3 and dielectric perceptivity ϵ = 12.46. Crystal and piezoelectric constants for model ling were taken from our previous work . GaAs WZ elastic stiffness coefficients were (GPa): C 11 = 147.6, C 12 = 40.6, C 13 = 33.4 and C 33 = 42.4.…”

“…[14] Recently, a piezoelectric structure based on an array of such NWs with an average PSC of d 33 ¼ 26 pC/N was demonstrated. [15] However, more detailed study of the piezoelectric properties of individual GaAs NWs is still required and is a topical problem. Therefore, the aim of our work was to perform a rigorous study of the generation of electric current in a single individual WZ GaAs NW deformed by an atomic force microscope (AFM) probe.…”

“…Crystal and piezoelectric constants for model ling were taken from our previous work. [15] GaAs WZ elastic stiffness coefficients were (GPa): C 11 ¼ 147.6, C 12 ¼ 40.6, C 13 ¼ 33.4 and C 33 ¼ 42.4. Piezoelectric constants were calculated using approach presented by Hubner [19] and their values were (C m À2 ): e 33 ¼ À0.295, e 31 ¼ 0.15.…”