perovskite; theory; solar cells; charge dynamics; ultrafast; hybrid; first principles; spectroscopy
Baldini Edoardo, Palmieri Tania, Dominguez Adriel, Ruello Pascal, Rubio Angel, Chergui Majed (2018), Phonon-Driven Selective Modulation of Exciton Oscillator Strengths in Anatase TiO 2 Nanoparticles, in Nano Letters
, 18(8), 5007-5014.
Pantaler Martina, Cho Kyung Taek, Queloz Valentin I. E., García Benito Inés, Fettkenhauer Christian, Anusca Irina, Nazeeruddin Mohammad Khaja, Lupascu Doru C., Grancini Giulia (2018), Hysteresis-Free Lead-Free Double-Perovskite Solar Cells by Interface Engineering, in ACS Energy Letters
, 3(8), 1781-1786.
Baldini Edoardo, Palmieri Tania, Pomarico Enrico, Auböck Gerald, Chergui Majed (2018), Clocking the Ultrafast Electron Cooling in Anatase Titanium Dioxide Nanoparticles, in ACS Photonics
, 5(4), 1241-1249.
Cho Kyung Taek, Grancini Giulia, Lee Yonghui, Oveisi Emad, Ryu Jaehoon, Almora Osbel, Tschumi Manuel, Schouwink Pascal Alexander, Seo Gabseok, Heo Sung, Park Jucheol, Jang Jyongsik, Paek Sanghyun, Garcia-Belmonte Germà, Nazeeruddin Mohammad Khaja (2018), Selective growth of layered perovskites for stable and efficient photovoltaics, in Energy & Environmental Science
, 11(4), 952-959.
Baldini E., Chiodo L., Dominguez A., Palummo M., Moser S., Yazdi-Rizi M., Auböck G., Mallett B.P.P., Berger H., Magrez A., Bernhard C., Grioni M., Rubio A., Chergui M. (2017), Strongly bound excitons in anatase TiO2 single crystals and nanoparticles, in Nature Communications
, 8(1), 13-13.
Baldini Edoardo, Palmieri Tania, Rossi Thomas, Oppermann Malte, Pomarico Enrico, Auböck Gerald, Chergui Majed (2017), Interfacial Electron Injection Probed by a Substrate-Specific Excitonic Signature, in Journal of the American Chemical Society
, 139(33), 11584-11589.
Baldini Edoardo, Dominguez Adriel, Chiodo Letizia, Sheveleva Evgeniia, Yazdi-Rizi Meghdad, Bernhard Christian, Rubio Angel, Chergui Majed (2017), Anomalous anisotropic exciton temperature dependence in rutile TiO2, in Physical Review B
, 96(4), 041204-041204.
Santomauro Fabio G., Grilj Jakob, Mewes Lars, Nedelcu Georgian, Yakunin Sergii, Rossi Thomas, Capano Gloria, Al Haddad André, Budarz James, Kinschel Dominik, Ferreira Dario S., Rossi Giacomo, Gutierrez Tovar Mario, Grolimund Daniel, Samson Valerie, Nachtegaal Maarten, Smolentsev Grigory, Kovalenko Maksym V., Chergui Majed (2017), Localized holes and delocalized electrons in photoexcited inorganic perovskites: Watching each atomic actor by picosecond X-ray absorption spectroscopy, in Structural Dynamics
, 4(4), 044002-044002.
Cho Kyung Teak, Trukhina Olga, Roldán-Carmona Cristina, Ince Mine, Gratia Paul, Grancini Giulia, Gao Peng, Marszalek Tomasz, Pisula Wojciech, Reddy Paidi Y., Torres Tomás, Nazeeruddin Mohammad Khaja (2017), Molecularly Engineered Phthalocyanines as Hole-Transporting Materials in Perovskite Solar Cells Reaching Power Conversion Efficiency of 17.5%, in Advanced Energy Materials
, 7(7), 1601733-1601733.
Cho Kyung Taek, Paek Sanghyun, Grancini Giulia, Roldán-Carmona Cristina, Gao Peng, Lee Yonghui, Nazeeruddin Mohammad Khaja (2017), Highly efficient perovskite solar cells with a compositionally engineered perovskite/hole transporting material interface, in Energy & Environmental Science
, 10(2), 621-627.
Cho Kyung Taek, Grancini Giulia, Lee Yonghui, Konios Dimitrios, Paek Sanghyun, Kymakis Emmanuel, Nazeeruddin Mohammad Khaja (2016), Beneficial Role of Reduced Graphene Oxide for Electron Extraction in Highly Efficient Perovskite Solar Cells, in ChemSusChem
, 9(21), 3040-3044.
M. Saliba et al. (2016), A molecularly engineered hole-transporting material for efficient perovskite solar cells, in Nature Energy
, 1, 15017.
C. Yi J. Luo S. Meloni A. Boziki N. Ahsari-Astani C. Graetzel S. M. Zakeeruddin U. Rothlisber (2016), Entropic stabilization of mixed A-cation ABX(3) metal halide perov-skites for high performance perovskite solar cells,, in Energy & Environmental
, Science 9, 656-662.
S. Meloni T. Moehl W. Tress M. Franckevicius M. Saliba Y.H. Lee P. Gao M.K. Nazeeruddin U. R (2016), Ionic polarization-induced current-voltage hysteresis in CH3NH3PbX3 perovskite solar cells, in Nature Comm.
, 7, 10334.
The present proposal aims at the fabrication of perovskite materials for solar cells and their characterization by cutting-edge time-resolved spectroscopic tools and theoretical modelling. It brings together leading research groups within EPFL having excellent complementary background for developing and investigating high efficiency hybrid organic-inorganic thin film solid-state perovskite solar cells to enhance the power conversion efficiency beyond 15%. In terms of fabrication, the strategy is to concentrate on samples prepared by dual-Source vapour deposition, two-step vapour deposition, and vapour-assisted solution processing methods (Dr. M. K. Nazeeruddin, EPFL Valais). The characterization aims at assessing the important aspects of the cell operation such as the exciton generation, migration and dissociation, or the equivalent for free charges, as well as electron and hole transfer at interfaces using time-resolved optical and core-level spectroscopies from femtoseconds (fs)/picoseconds (ps) to the nanoseconds (Prof. M. Chergui). Photoluminescence and transient absorption studies will be used to identify the global charge carrier dynamics. For a finer identification of the fate of charge carriers (holes and electrons), fs/ps X-ray absorption spectroscopy and electron-energy-loss-spectroscopy (EELS) will be used. These studies will be carried out on pure perovskite materials and on the complete cell. First principles materials and device modelling (Prof. Ursula Roethlisberger) will provide a comprehensive understanding of the fundamental optical and electronic processes occurring in the materials and the operation of the complete devices. In particular, density functional theory (DFT) and time-dependent DFT (TDDFT) electronic structure calculations will be performed to characterize the structural, electronic and optical properties of perovskite crystals and of their interfaces with the electron/hole blocking materials. Time-propagation TDDFT (TP-TDDFT) will be used for simulating charge relaxation and transport, as well as the interfacial charge injection (electrons or holes). Because of the novelty of these studies, we will proceed in a step-wise fashion, first concentrating on the charge carrier dynamics in pure perovskites of the type CH3NH3PbI3, prior to investigating the important interfacial dynamics. The ambitious goal of the project is to take the perovskite-based solar cell beyond the present day performance by a detailed experimental and theoretical understanding of the charge separation mechanisms. This know-how will feedback into the design and optimization of the solar cells. This will be achieved by: i) developing new, ideally optimized materials, perovskite absorbers and hole-conductors; ii) probing and understanding the fundamental processes occurring in the materials and in operational solar cells to give a rational approach to the design and; iii) implementation of new materials delivering improved performance of 18% or more.