László Forró
Laboratory of Physics of Complex Matter,
Ecole Polytechnique Fédérale de Lausanne, CH-1015, Lausanne
In the last few years, the organolead halide perovskite CH3NH3PbI3 and its derivatives have been found to be very efficient light harvesters and ambipolar semiconductors revolutionizing the field of solid-state solar cells. Its low temperature fabrication process allowed to design simpler solar cell structures (i.e.from mesoscopic to planar junctions) which yielded efficiencies exceeding 20%. The major research area in this field is photovoltaic device engineering although other applications as solar water splitting, field effect transistors (FETs), ultra-broadband photodetectors, thermoelectric devices, light emitting diodes and lasers are being explored as well.
Recently, we have shown that nanowires of this photovoltaic perovskite can be synthesized, which in association with carbon nanostructures (carbon nanotubes and graphene) make outstanding composites with rapid and strong photoresponse. They can serve as conducting electrodes, or as central components of detectors. The performance of several miniature devices based on these composite structures will be demonstrated. Our latest findings on the guided growth of perovskite nanowires by solvatomorphgraphoepitaxy will be presented. This method turned out to be a fairly simple approach to overcome the spatially random surface nucleation. The process allows the synthesis of extremely long (centimeters) and thin (a few nanometers) nanowires with a morphology defined by the shape of nanostructured open fluidic channels. This low-temperature solution-growth method could open up an entirely new spectrum of architectural designs of organometallic-halide-perovskite-based heterojunctions and tandem solar cells, LEDs and other optoelectronic devices.
Acknowledgement: This work is done in collaboration with Endre Horvath, Massimo Spina, Alla Arakcheeva, Balint Nafradi, Eric Bonvin1, Andrzej Sienkievicz, Zsolt Szekrenyes, Hajnalka Tohati, Katalin Kamaras, Eduard Tutis, Laszlo Mihaly and Karoly Holczer The research is supported by the ERC Advanced Grant (PICOPROP670918).
[1] Horvath et al. Nano Letters, 2014, 14 (12), 67616766
[2] Spina et al. Nanoscale, 2016, 8, 4888
[3] Spina et al. Small, 2015, 11, 4824-4828
[4] Spina et al. Scientifc Reports, 2016, 6
