First demonstration of improvement in hole conductivity in c-plane III-Nitrides through application of uniaxial strain

Abstract

Hole transport in III-Nitrides (III-Ns) is dominantly dependent on the large effective mass of holes and thus, results in a low hole mobility. First principle band structure calculations suggest that under uniaxial strain, the valence band degeneracy can be broken and the light hole band with lower hole effective mass can be obtained as the topmost valence band. In this work, we experimentally demonstrate the improvement in hole conductivity under the application of uniaxial strain in III-Ns. We obtained approximately 25%–50% lower sheet resistance with uniaxially strained InGaN layers compared to planar biaxially strained InGaN layers.