In-plane coupling effect in InAs/GaAs quantum dots arrays for intermediate band solar cell

Laterally coupled semiconductor quantum dot (QD) arrays emerged recently as promising structures for the next generation of high efficiency intermediate band solar cell (IBSC), due to their ability to facilitate the formation of in-plane minibands with large vertical inter-layer distance to prevent the strain field from influencing its neighboring QD array layers. The lateral quantum coupling effect, which exists between states in QDs of an array, influences the electronic and optical properties of such structures. We present here a method based on multi-band k·p Hamiltonian combined with periodic boundary conditions, applied to predict the electronic and optical properties of InAs/GaAs QDs based lateral QD arrays. The absorption coefficients under different in-plane coupling strength were derived and the corresponding photovoltaic conversion efficiencies were also estimated using drift-diffusion transportation theory. Special attention was paid on the transition between IB to continuum states in conduction band.