Figure 1. Materials design and fabrication.

(a) Schematic of the fabrication of a polycrystalline film from colloidal CdTe nanocrystals. Chloride-capped CdTe colloidal nanocrystals were spin coated onto a substrate forming a film, which was subsequently annealed at 350 °C in an argon environment for 0.5–5 min. (b) Scanning electron microscopy (SEM) image of the polycrystalline film. Red line and arrow represent a pathway along GBs for electron percolation.