We examine the influence of the wetting layers (WLs) and the quantum dot (QD) size distribution on the sub-bandgap external quantum efficiency (EQE) of QD solar cells. We use a finite-element Schrdinger-Poisson model that considers QD and wetting layer shapes, sizes, and spacings from cross-sectional scanning tunneling and atomic force micrographs. A comparison between experiments and computations reveals an insignificant contribution of the WL to the sub-bandgap EQE and a broadening of sub-bandgap EQE associated with a variation in QD sizes in the growth direction.
ASJC Scopus subject areas
- Physics and Astronomy(all)