Proceedings of 6th International Conference on Hybrid and Organic Photovoltaics (HOPV14)
Publication date: 1st March 2014
Recently, organometal trihalide perovskite-based solid-state hybrid solar cells have attracted unexpected increasing interest because of the high efficiency over 15% and low cost for preparation[1-3]. The high efficiency was thought to mainly originate from the strong optical absorption over a broader range (up to 800 nm) and longer lifetimes of photoexcited charge carriers (in the order of 10 ns – 100 ns) of the perovskite absorbers. On the other hand, charge separation and recombination dynamics are also key factors for achieving the high efficiency, which have not been studied systematically. To search for the high efficiency mechanism of the perovskite-based hybrid solid-state solar cells and therefore find similar materials for the next generation solar cells, we have systematically investigated the charge separation and recombination dynamics in CH3NH3PbClI2 perovskite hybrid solid-state solar cells by using femtosecond and nanosecond Transient absorption (TA) techniques for a time scale of sub-picoseconds to milliseconds[4]. Several kinds of samples containing CH3NH3PbClI2 deposited on different metal oxide mesoporous films of TiO2 and Y2O3 with and without a hole transport material (HTM) of spiro-OMeTAD were studied. Electrons in perovskite could be injected into TiO2 and could not be injected into Y2O3 because the conduction band edge of CH3NH3PbClI2 is higher than that of TiO2 but lower than that of Y2O3. By choosing the probe light wavelength from the visible region to the NIR region in the TA measurements, the relaxation dynamics of electrons in Perovskite and/or those injected into TiO2, and the relaxation dynamics of holes in spiro-OMeTAD were detected. Photoexcited charge carrier lifetimes in perovskite, charge separation and charge recombination at TiO2/perovskite and perovskite/spiro-OMeTAD interfaces were clarified. We have compared the photoexcited charge carrier dynamics between two TiO2/ CH3NH3PbClI2/spiro-OMeTAD solar cells. One solar cell showed an energy conversion efficiency of 6% (cell A) and another showed an efficiency of 9% (cell B), and the difference in the efficiency was due to the great difference in the incident photon to current conversion efficiency (IPCE) and thus the resultant short circuit current density (Jsc). Charge separation and charge collection efficiencies were discussed quantitatively for the two cells. We found that the bottleneck for the IPCE and Jsc of the preovskite solar cells was charge recombination of electrons in TiO2 and holes in spiro-OMeTAD, i.e. the charge collection efficiency rather than charge separation efficiency. Our findings indicate that high efficiency can be achieved by suppressing the recombination through appropriate interfacial engineering.
Schematic illustration of photoexcited electron injection and recombination dynamics in two TiO2/CH3NH3PbClI2/spiro-OMeTAD solar cells A (a) and B (b).
1. Lee, M. M.; Teuscher, J.; Miyasaka, T.; Murakami, T. N.; Snaith, H. J. Efficient Hybrid Solar Cells Based on Meso-Superstructured Organometal Halide Perovskites. Science 2012, 338, 643-647. 2. Kim, H.-S.; Lee, C.-R.; Im, J.-H.; Lee, K.-B.; Moehl, T.; Marchioro, A.; Moon, S.-J.; Humphry-Baker, R.; Yum, J.-H.; Moser, J. E.; Gratzel, M.; Park, N.-G. Lead Iodide Perovskite Sensitized All-Solid-State Submicron Thin Film Mesoscopic Solar Cell with Efficiency Exceeding 9%. Sci. Rep. 2012, 2, 591. 3. Burschka, J.; Pellet, N.; Moon, S.-J.; Humphry-Baker, R.; Gao, P.; Nazeeruddin, M. K.; Gratzel, M. Sequential deposition as a route to high-performance perovskite-sensitized solar cells. Nature 2013, 499, 316-319. 4.Shen Q., Ogomi Y., Tsukamoto S., Kukihara K., Oshima T.,Osada N., Yoshino K., Katayama K., Toyoda T., Hayase S., submitted.
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.