Slower carriers limit charge generation in organic semiconductor light-harvesting systems.

ABSTRACT: Blends of electron-donating and -accepting organic semiconductors are widely used as photoactive materials in next-generation solar cells and photodetectors. The yield of free charges in these systems is often determined by the separation of interfacial electron-hole pairs, which is expected to depend on the ability of the faster carrier to escape the Coulomb potential. Here we show, by measuring geminate and non-geminate losses and key transport parameters in a series of bulk-heterojunction solar cells, that the charge-generation yield increases with increasing slower carrier mobility. This is in direct contrast with the well-established Braun model where the dissociation rate is proportional to the mobility sum, and recent models that underscore the importance of fullerene aggregation fo

SUBMITTER: Stolterfoht M 

PROVIDER: S-EPMC4919513 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature