Role of mid-gap states in charge transport and photoconductivity in semiconductor nanocrystal films.

ABSTRACT: Colloidal semiconductor nanocrystals have attracted significant interest for applications in solution-processable devices such as light-emitting diodes and solar cells. However, a poor understanding of charge transport in nanocrystal assemblies, specifically the relation between electrical conductance in dark and under light illumination, hinders their technological applicability. Here we simultaneously address the issues of 'dark' transport and photoconductivity in films of PbS nanocrystals, by incorporating them into optical field-effect transistors in which the channel conductance is controlled by both gate voltage and incident radiation. Spectrally resolved photoresponses of these devices reveal a weakly conductive mid-gap band that is responsible for charge transport in dark. The mech

SUBMITTER: Nagpal P 

PROVIDER: S-EPMC3195212 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature