Charge Dynamics in Colloidal Quantum Dots: Recombination, Trapping and Multiple Exciton Generation
Colloidal quantum dots (CQDs) are semiconductor crystals, the nanometre-scale size of which both allows their absorption edge to be controlled during growth and enhances the yield of multiple exciton generation. These properties, combined with the facile and scalable solution-phase methods by which they can be made and processed, make CQDs promising candidates for the light-absorbing species in third-generation photovoltaic devices. However, the effectiveness of CQDs in this role depends crucially on the relative rates of a number processes affecting the charges photogenerated in CQDs. We describe the most important of these processes and how they can be optimised to enhance solar cell efficiency by engineering the structure and composition of CQDs.