Study of Static and Dynamic Disorder in Organic-Inorganic Halide Perovskites

Tereza Schönfeldová^a, Jakub Holovský^a^,^b, Zdeňka Hájková^a, Lucie Abelová^a^,^b, Neda Neykova^a, Ha Stuchlíková^a, Jan Kočka^a, Stefaan De Wolf^c, Antonín Fejfar^a, Martin Ledinský^a

^aLaboratory of Nanostructures and Nanomaterials, Institute of Physics, Academy of Sciences of the Czech Republic, v. v. i., Cukrovarnická 10, 162 00 Prague, Czech Republic

^bFaculty of Electrical Engineering, Czech Technical University in Prague, Prague, Czech Republic

^cKing Abdullah University of Science and Technology (KAUST) - Saudi Arabia, 4700 King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia

International Conference on Hybrid and Organic Photovoltaics
Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV18)

Benidorm, Spain, 2018 May 28th - 31st

Organizers: Emilio Palomares and Rene Janssen

Oral, Tereza Schönfeldová, presentation 107
DOI: https://doi.org/10.29363/nanoge.hopv.2018.107
Publication date: 21st February 2018

Using two different techniques, Fourier-transform photocurrent spectroscopy (FTPS) and photoluminescence (PL), we have probed the temperature dependence of methylammonium lead iodide (MALI) absorption spectra to be able to distinguish the static and dynamic part of Urbach energy. We extract the Urbach energy as the reciprocal value of the slope of the absorption at the band edge plotted in logarithmic scale. Its value depends on the material disorder and generally correlates well with the loss in the open-circuit voltage (V_OC) of optimized cells, compared to their bandgap, for a given photovoltaic technology [1]. When cooling perovskites, we find a strong decrease in their Urbach energy and a slow decrease of their optical band gap energy. We observe that all absorption curves measured at different temperatures intersect at one point called the Urbach focus, which was in our case at 1.52 eV, which represents a general lower limit for the optical band gap in MALI. Fitting Urbach energies from PL measurements we obtain phonon energies of 135 ± 20 cm^-1 [2], which implicates that the dynamic disorder of MALI is given by cage vibrations. Finally, we will show and discuss that the density of active static defects in perovskites is very low in comparison to other materials used for solar cells, especially for a solution processed one. These results will help establish practical efficiency limits of perovskite solar cells, as compared to the Shockley-Queisser limit.

[1] S. De Wolf et al.: J. Phys. Chem. Lett. 5 (2014) 1035.

[2] M. Ledinský et al.: J. Phys. Chem. Lett. 6 (2015) 401.

nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.

MATSUS

Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.

International Conference on Hybrid and Organic Photovoltaics

International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.

Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics

The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.

International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics

The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.