Quantum Dots for Solar Cells

The highly tunable nature of the electronic band structure of quantum dots (QDs) is promising for many reasons. For a given composition, alteration of the size of the QD alone will change the light absorbed and emitted by the QD. Upon entering the ultrasmall regime, sub 2 nm radii, CdSe QDs have been shown to emit white light, i.e. all wavelengths in the visible regime, upon exposure to UV light. A number of techniques have been employed to probe the nature of the light-matter interactions of these systems including time correlated single photon counting (TCSPC), ultraviolet-visible (UV-vis) and photoluminescence (PL) spectroscopy, transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS).‚Äč Understanding of the intricate band structure of these QDs will allow for optimization of light harvesting devices such as solar cells.