%0 Journal Article
%T Electronic properties and morphology of Cu-Phthalocyanine - C$_{60}$ composite mixtures
%A Friedrich Roth
%A Cosmin Lupulescu
%A Tiberiu Arion
%A Erik Darlatt
%A Alexander Gottwald
%A Wolfgang Eberhardt
%J Physics
%D 2014
%I arXiv
%R 10.1063/1.4861886
%X Phthalocyanines in combination with C$_{60}$ are benchmark materials for organic solar cells. Here we have studied the morphology and electronic properties of co-deposited mixtures (blends) of these materials forming a bulk heterojunction as a function of the concentration of the two constituents. For a concentration of 1:1 of CuPc:C$_{60}$ a phase separation into about 100 nm size domains is observed, which results in electronic properties similar to layered systems. For low C$_{60}$ concentrations (10:1 CuPc:C$_{60}$) the morphology, as indicated by Low-Energy Electron Microscopy (LEEM) images, suggests a growth mode characterized by (amorphous) domains of CuPC, whereby the domain boundaries are decorated with C$_{60}$. Despite of these markedly different growth modes, the electronic properties of the heterojunction films are essentially unchanged.
%U http://arxiv.org/abs/1401.1967v1