Nonequilibrium site distribution governs charge-transfer electroluminescence at disordered organic heterointerfaces.

ABSTRACT: The interface between electron-donating (D) and electron-accepting (A) materials in organic photovoltaic (OPV) devices is commonly probed by charge-transfer (CT) electroluminescence (EL) measurements to estimate the CT energy, which critically relates to device open-circuit voltage. It is generally assumed that during CT-EL injected charges recombine at close-to-equilibrium energies in their respective density of states (DOS). Here, we explicitly quantify that CT-EL instead originates from higher-energy DOS site distributions significantly above DOS equilibrium energies. To demonstrate this, we have developed a quantitative and experimentally calibrated model for CT-EL at organic D/A heterointerfaces, which simultaneously accounts for the charge transport physics in an energetically disord

SUBMITTER: Melianas A 

PROVIDER: S-EPMC6876215 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature