Universal Trapping Mechanism in Semiconductor Nanocrystals.

Sizetunability of the optical properties and inexpensive synthesismake semiconductor nanocrystals one of the most promising and versatilebuilding blocks for many modern applications such as lasers, single-electrontransistors, solar cells, and biological labels. The performance ofthese nanocrystal-based devices is however compromised by efficienttrapping of the charge carriers. This process exhibits different featuresdepending on the nanocrystal material, surface termination, size,and trap location, leading to the assumption that different mechanismsare at play in each situation. Here we revolutionize this fragmentedpicture and provide a unified interpretation of trapping dynamicsin semiconductor nanocrystals by identifying the origins of this sofar elusive detrimental process. Our findings pave the way for a generalsuppression strategy, applicable to any system, which can lead toa simultaneous efficiency enhancement in all nanocrystal-based technologies. [ABSTRACT FROM AUTHOR]