24 November, Friday in 11:30 at scientific council
V pyatnitsu, 10 noyabrya, v 13:30, v konferents-zale IFTT sostoitsya
SOVMESTNYI SPETsIAL’NYI SEMINAR IFTT/ITF:
"Advances and Promises of Layered Halide Hybrid Perovskite Semiconductors"
Doklad sdelaet Sergei Tret’yak,
Electrochemical Energy Storage Center (CEE), Skolkovo Institute of Science and Technology, Russia.
ON LEAVE: Theoretical Division, Center for Nonlinear Studies and Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos NM, 87545, http://faculty.skoltech.ru/people/sergeitretiak, http://cnls.lanl.gov/~serg , Tretiak@skoltech.ru
Hybrid organic−inorganic perovskites (HOPs) have demonstrated an extraordinary potential for clean sustainable energy technologies and low-cost optoelectronic devices such as solar cells, light emitting diodes, detectors, sensors, ionic conductors, etc. Despite excellent properties, the main weakness of three dimensional (3D) HOPs is poor photo and environmental stabilities. Layered two-dimensional (2D) HOPs offer attractive alternatives for solar cells and light-emitting devices being largely immune to the stability issues. This talk overviews the main features of the optoelectronic properties of layered HOP by combining solid-state physics concepts with simulation tools based on density functional theory. A comparison between layered and 3D HOP highlights differences and similarities such as spin-orbit effects, quantum and dielectric confinements and excitonic properties. Experimentally, 2D HOP was incorporated into a photovoltaic device that exhibited a world-record efficiency (13% in the category of 2D perovskite materials) and stability for over 3 month under constant light illumination and 65% humidity. The photophysics of these materials is defined by an interplay of strongly bound excitons and lower-energy states associated with the edges of the perovskite layers. The latter provide a direct pathway for dissociating excitons into longer-lived free carriers that substantially improve the performance of optoelectronic devices. Our theoretical simulations rationalize specifics of electronic structure of these materials, dynamics and a role of interfacial states. We also outline specific ways to rationally control geometry of edges in 2D HOP materials via external fields, contact interfaces and composition of organic compound. Overall, our results provide insights towards the material design for various applications.
W. Nie, et al, "High-efficiency solution-processed perovskite solar cells with millimeter-scale grains", Science, 347, 522 (2015).
H. Tsai, et al, "High-efficiency two-dimensional Ruddlesden-Popper perovskite solar cells", Nature, 536, 312 (2016).
J.-C. Blancon, et al "Extremely efficient internal exciton dissociation through edge-states in layered 2D perovskites" Science, 355, 1288 (2017).
L. Pedesseau, et al, "Advances and Promises of Layered Halide Hybrid Perovskites Semiconductors" ACS Nano (Review), 10, 9776 (2016).
M. Kepenekian et al "Surface reconstruction and exciton dissociation in layered Ruddlesden-Popper hybrid perovskites" (2017, submitted)
Our congratulations to Lev N. Shchur with his election as an APS Fellow “for innovative use of computer simulations and the development of superior random number generators for their use in statistical physics”.
Pozdravlyaem Aleksandra Yur’evicha Kamenshchika s prisuzhdeniem Premii imeni A.A. Fridmana 2017 za tsikl rabot «Novye napravleniya v kosmologii rannei i sovremennoi Vselennoi».
Our congratulations to Alexei Alexandrovich Starobinsky, who has been elected to foreign associates of the National Academy of Sciences.
For more information see site of the Academy.
Vchera, 29 marta 2017 goda, skonchalsya Aleksei Alekseevich Abrikosov, akademik, laureat Nobelevskoi premii, odin iz ottsov-osnovatelei Instituta teoreticheskoi fiziki.
Administratsiya ITF vyrazhaet glubokie soboleznovaniya rodnym i blizkim Alekseya Alekseevicha.
Sotrudniki ITF vsegda budut pomnit’ ob Aleksee Alekseeviche, kak o zamechatel’nom uchenom, a takzhe o tom neotsenimom vklade, kotoryi Aleksei Alekseevich vnes v sozdanie i razvitie Instituta.
Segodnya, 28 dekabrya 2016 goda, skonchalsya Lev Petrovich Gor’kov, odin iz ottsov-osnovatelei Instituta teoreticheskoi fiziki.
Sotrudniki ITF vsegda budut pomnit’ o L’ve Petroviche, kak o zamechatel’nom uchenom, a takzhe o tom neotsenimom vklade, kotoryi Lev Petrovich vnes v sozdanie i razvitie Instituta.
Nekrolog sm. na saite UFN ili Physics Today.
Our congratulations to Alexei Kitaev, laureate of The 2017 Oliver E. Buckley Condensed Matter Physics for "theories of topological order and its consequences in a broad range of physical systems. For more information see site of The Oliver E. Buckley Condensed Matter Physics Prize.
Our congratulations to Paul B. Wiegmann, laureate of The 2017 Lars Onsager Prize "for the pioneering discovery of the exact solution of the Kondo and Anderson models, opening a new field of exact treatments of quantum impurity systems". For more information see site of The Lars Onsager Prize.