Dodecahedron CsPbBr3 Perovskite Nanocrystals Enable Facile Harvesting of Hot Electrons and Holes

This Letter reports the facile harvesting of hot carriers (HCs) in a composite of 12-faceted dodecahedron CsPbBr3 nanocrystal (NC) and a scavenger molecule. We recorded -3.3 X 1011 s-1 HC cooling rate in NC when excited with -1.4 times the band gap energy (Eg), increasing to >3 X 1012s-1 in the presence of scavengers at high concentration due to the HC extractions. Since the observed intrinsic charge transfer rate (-1.7 X 1012 s-1) in our NC- scavenger complex is about an order of magnitude higher than the HC cooling rate (-3.3 X 1011 s-1), carriers are harvested before their cooling. Further, a fluorescence correlation spectroscopy study reveals NC tends to form a quasi-stable complex with a scavenger molecule, ensuring charge transfer completed (zct approximate to 0.6 ps) much before the complex breaks apart (>600 mu s). The overall results of our study highlight the promise shown by 12-faceted NCs and their implications in modern applications, including hot carrier solar cells.