Surface states of wurtzite semiconductor nanowires with identical lateral facets: A transfer-matrix approach

The focus of this paper is to investigate systematically surface states of semiconductor nanowires of wurtzite crystals with identical lateral surfaces. We first calculate the surface spectrum of a semi-infinite crystal. Then, using cyclic boundary conditions, we calculate the quantized spectrum of the surface states in nanowires. We find that the spectrum of the nanowire surfaces consists of a number of quantized levels inside the band gap. We further study absorption coefficients due to dipole transitions between the surface states in such nanowires. We demonstrate that such transitions lead to absorption above the fundamental band edge transition. Our calculations also show that the absorption coefficient induced by the transitions between the surface states depends weakly on the light polarization.