Fig. 2
From: Recent Progress Towards Quantum Dot Solar Cells with Enhanced Optical Absorption
a SEM micrographs of the surface plane on top of 400-stack In0.4Ga0.6As QD structures. The ultra-high stacked structures have good surface morphologies even after the stacking of 300 or 400 QD layers. b Enlarged cross-sectional STEM images of bottom portions of 300-stack In0.4Ga0.6As QD layers. No dislocations were generated after the stacking of 300 layers, even though no strain balancing was employed during the growth. c EQE spectra of multi-stacked In0.4Ga0.6As QD solar cells and a GaAs reference cell. The EQEs of the 10-, 20-, 30-, 50-, 100- and 150-stack In0.4Ga0.6As QD solar cells are indicated. Reproduced from Ref. [12] with permission from The Royal Society of Chemistry