Structural and Chemical Assessment of InAs/AlGaAs quantum Dot Structures for Enlarged Bandgap Intermediate Band Solar Cells

An Intermediate Band (IB) solar cell (SC) consists of an IB material situated between the n- and p-type regions of a host semiconductor. The IB material has a band of states in the energy gap (Eg) of the host semiconductor, which allow an electron-hole pair generation by means of the absorption of two photons of energy lower than Eg. For this kind of SC, Luque and Martì [1] demonstrated a limiting efficiency of 63.2%, in comparison to the Shockley-Queisser limit of 40.7% [2] for a conventional single-gap solar cell under the same operating conditions.