Chapter 3: Thin-Film Colloidal Quantum Dot Solar Cells

In under a decade, progress in quantum dot (QD) solar cell design and fabrication have increased PbS QD solar cell efficiencies from 3% to 11.3%. Such solar cells based on colloidal quantum dots offer the potential for a higher limiting power conversion efficiency through the enhancement of multiple exciton generation (MEG). In the MEG process, one photon produces two or more excitons that can contribute to power generation when the photon energy exceeds the semiconductor bandgap. The efficiency of the MEG process has also increased through the design and fabrication of new nanostructures. The fast pace at which QD devices are improving and the potential for a higher limiting efficiency-as MEG can increase the limiting power conversion efficiency (PCE) for a single-junction solar cell from 33% to ~. 45%-demonstrate the large potential of these systems.