摘要：Nanocrystal quantum dots (QD) show great promise toward improving solar cell efficiencies through the use of quantum confinement to tune absorbance across the solar spectrum and enable multi-exciton generation. Despite this remarkable potential for high photocurrent generation, the achievable open-circuit voltage ( V oc) is fundamentally limited due to non-radiative recombination processes in QD solar cells. Here we report the highest open-circuit voltages to date for colloidal QD based solar cells under one sun illumination. This V oc of 692 ± 7 mV for 1.4 eV PbS QDs is a result of improved passivation of the defective QD surface, demonstrating as a function of the QD bandgap ( E g). Comparing experimental V oc variation with the theoretical upper-limit obtained from one diode modeling of the cells with different E g, these results clearly demonstrate that there is a tremendous opportunity for improvement of V oc to values greater than 1 V by using smaller QDs in QD solar cells.
