Mircea Cotlet, Brookhaven National Laboratory
Energy Transfer from CdSe/ZnS Quantum Dots to Single and Few Layers of SnS2 Nanosheets: From Single Quantum Dots to Device
Written by Tyler W. Farnsworth
The bandgap tunability of the two-dimensional metal dichalcogenides makes them interesting platforms for solar energy conversion. However, the same qualities (i.e., low-dimensions) that lend to the bandgap tunability are also a drawback. The thin nanomaterials have a low absorption cross-section, making it difficult to implement them into solar cell technology. Mircea Cotlet (Brookhaven National Laboratory) investigated this problem and proposed a new solar cell architecture that combines SnS2 with CdSe/ZnS quantum dots (QDs). He found that doping 2D materials with bandgap-matched semiconductor QDs increased the absorption and improved device performance. He observed photoluminescence quenching of the QDs when in contact with SnS2 and used this as the basis for his mechanism study. Cotlet presented experimental results of PL blinking of the QDs and proposed that monitoring PL blinking is a straightforward method to discriminate between energy transfer (FRET) and charge transfer (CT) in 2D hybrids of QDs and 2D materials.