Proceedings of nanoGe September Meeting 2015 (NFM15)
Publication date: 8th June 2015
We have elucidated the charge-carrier dynamics in organic-inorganic metal halide perovskites that are implemented as active light-harvesting materials in high-efficiency solar cells. We found that charge carriers can travel over distances of up to a micron in solution-processed CH3NH3PbI3−xClx perovskite absorbers [1], thus making these materials suitable for planar-heterojunction solar cells. We demonstrate [2,3] that this effect arises from a combination of high charge-carrier mobility (11.6 cm2 V−1 s−1 for mesostructured solution-processed, and 33 cm2 V−1 s−1 for evaporated CH3NH3PbI3−xClx films) and abnormally low bi-molecular charge recombination rates that defy the Langevin limit by at least four orders of magnitude. We further show that CH3NH3PbI3−xCl films exhibit extraordinarily low energetic disorder, with an emission spectrum that is predominantly homogenously broadened through strong coupling of charge-carriers to phonons [4]. With the observed spectral width of 103 meV, such gain media can sustain amplification of light pulses as short as 6.4 fs, opening a perspective for electrically-pumped femtosecond-pulsed lasers.In addition, we have examined the charge-carrier dynamics in the lead-free perovskite CH3NH3SnI3 for which solar cells processed on a mesoporous TiO2 scaffold were shown to reach efficiencies of over 6% [5]. Using transient THz spectroscopy, we find that the ultrafast charge-dynamics are dominated by a first-order decay that may originate from electron recombination with an unintentional hole doping density of ~1018 cm-3. We establish an effective charge-carrier mobility of 1.6 cm2 V−1 s−1, yielding a charge-carrier diffusion length of 30nm [5]. We show that if mono-molecular processes arising from unintentional doping or charge trapping are resolved, charge diffusion lengths in excess of one micron can be reached for CH3NH3SnI3, opening the way for lead-free perovskite photovoltaics with planar-heterojunction architecture.
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.
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.
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.