László Forró (EPFL, Switzerland)
Wed, 09/03/2016 – 11:00am to 12:00pm
Physics Conference Room (S11-02-07)
Recently, it has been shown by the Snaith  and Graetzel  groups that CH3NH3PbI3 is very promising material in photovoltaic devices reaching light conversion efficiency (η) up to 21%. A strong research activity has been focused on the chemistry of the material to establish the most important parameters which could further improve η and to collect photons from a broad energy window. The major trend in this field is in photovoltaic device engineering although the fundamental aspects of the material are not yet understood. In my lab we have devoted considerable effort to the growth of high quality single crystals at different length scales, ranging from large bulk crystals (up to 100 mm3) through nanowires [3,4] down to quantum dots of tens of nanometers of linear dimensions. The structural tunability of the material allows to study a broad range of physical phenomena including electrical and thermal transport, magnetism and optical properties which will be reported in this presentation together with some device applications .
Acknowledgement: The work has been performed in collaboration with Endre Horvath, Massimo Spina, Balint Nafradi, Alla Araktcheva, Andrea Pisoni, Jacim Jacimovic and the Van der Marel group. This work was partially supported by the ERC Advanced Grant (PICOPROP#670918).
1. Lee, M. M. et al.,Science 338, 643-647 (2012).
2. Stranks, S. D. et al.. Science, 342, 341−344, (2013).
3. Horvath et al., Nano Letters 14, 6761, (2015)
4.Spina et al., (2016) Scientific Reports, 6, 1
5.Spina et al., (2015) Small, 11, 4823
Lazslo Forro is a Full Professor at the Institute of Physics of the Ecole Polytechnique Federale de Lausane (EPFL), in Switzerland, and director of the EPFL Laboratory for the Physics of Complex Materials (LPCM). The activity of the LPCM covers a broad range of topics, from superconductivity to the movement of dislocations, to living cells, all with complexity as the common denominator. The lab provides a single crystal growth facility with nano-sized to macroscopic samples, synthesizing more than 100 different compounds. Through studying the basic physical properties of novel electronic materials like cuprate or pnictide superconductors, organic kagome lattices, low-dimensional conductors, graphene, magnetic semiconductors or anatase single crystals, one of the goals of LPCM beyond the exciting physics they reveal, is to learn how one can improve the materials quality. The group is also strongly involved in establishing bridges between the physical and biological sciences, the hard and soft matter themes. One result of this effort is the bi-annual organization of the international conference “From Solid State to Biophysics”.