Fig. 4.
Schematic diagram of hot versus cold electron injection and its effect on maximum obtainable open circuit voltage (Voc,MAX) in a photovoltaic device (A). Depiction (B) and ultrafast transient rise times (C) of multiple sizes of CdSe quantum dot excited at various heights above the band edge utilizing a single pump energy. Rise time of transient versus energy differential between quantum dot bandgap and pump pulse (D) and demonstration of a lack of hot-electron injection in CdSe-SnO2, CdSe-TiO2, and CdSe-ZnO systems (E). Note, C and D collected from CdSe in toluene solution.