Theoretical study of multi-band solar cells with a single PbS quantum dot superlattice film as a light absorption layer

Abstract

Theoretical studies have predicted that quantum dot superlattice (QDSL) intermediate band solar cells (IBSC) have high power conversion efficiencies (PCE), but it has not been considered what intermediate band (IB) structure can actually be reproduced. We theoretically examined the characteristics of solar cells manufactured using a superlattice composed of colloidal PbS quantum dots (QDs), and found that PCE of 50% or more can be realized in a single junction structure with multi-step light absorption via IBs. PCE has been reported to increase as the number of IBs increases, but we found that this is not always the case due to the balance of the number of transition carriers in IBs.