Dresden 2017 – wissenschaftliches Programm
CPP 13.19: Poster
Montag, 20. März 2017, 18:30–21:00, P1A
Doping design for hole transport materials in perovskite solar cells — •Lorena Perdigón Toro, Christian M. Wolff, Malavika Arvind, and Dieter Neher — University of Potsdam, Soft Matter Physics
In planar perovskite solar cells, the active perovskite semiconductor is usually sandwiched between an organic hole transport material (HTM) and an electron transport material (ETM). The correct choice of these materials has been shown to be crucially important when aiming at high device efficiencies. A promising HTM is the polymeric hole conductor poly(triaryl amine) (PTAA), which given its energetic levels has been shown to be a suitable choice as hole transport and electron-blocking layer. Nonetheless, the relatively low hole mobility of PTAA can be limiting to the performance of the devices, particularly the fill factor and open-circuit voltage. In order to provide sufficient coverage and prevent shunt pathways, thicker hole transport layers (>20 nm) can be efficiently applied provided their mobility can be increased. Therefore, we employ the widely studied electron acceptor F4TCNQ and the strong Lewis acid tris(pentafluorohenyl)borane as dopants for PTAA. Optical spectroscopy of doped solutions and layers insights into the underlying doping mechanisms. The impact of doping on layer morphology is studied by AFM, while the electrical properties are studied with systematic conductivity measurements at different operational conditions (e.g. elevated temperatures). Doped layers are optimized in working devices for highly efficient perovskite solar cells, reaching efficiencies above 18%.