14 research outputs found
Impact of microstructure on the electron-hole interaction in lead halide perovskites
Despite the remarkable progress in the performance of devices based on the lead halide perovskite semiconductor family, there is still a lack of consensus on their fundamental photophysical properties. Here, using magneto-optical transmission spectroscopy we elucidate the impact of the microstructure on the Coulomb interaction between photo-created electron-hole pairs in methylammonium lead triiodide (MAPbIâ) and the triple-cation lead mixed-halide composition, Csâ.ââ
(MAâ.ââ FAâ.ââ)â.ââ
Pb(Iâ.ââBrâ.ââ)â (Cs: cesium, MA: methylammonium, FA: formamidinium) by investigating thin films with a wide range of grain sizes from tens of nanometers to microns. At low temperatures, in which thermal fluctuations of the interactions are frozen and the rotational disorder of the organic cation is negligible, the exciton binding energy and reduced effective mass of carriers remain effectively unchanged with grain size. We conclude that the microstructure plays a negligible role in the Coulomb interaction of the photo-created electron-hole pairs, in contrast to previous reports. This renewed understanding of the relationship between these fundamental electronic properties and the microstructure is critical for future fundamental studies and improving device design.The authors acknowledge support from the Australian Government through the Australian Renewable Energy Agency (ARENA) and the Australian Centre for Advanced Photovoltaics (ACAP). The views expressed herein are not necessarily the views of the Australian Government, and the Australian Government does not accept responsibility for any information or advice contained herein. S. D. S. acknowledges funding from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme (FP7/2007-2013) under REA grant agreement number PIOF-GA-2013-622630. This work was partially supported by ANR JCJC project milliPICS, the RĂ©gion Midi-PyrĂ©nĂ©es under contract MESR 13053031, BLAPHENE project under IDEX program Emergence and Programme des Investissements d'Avenir under the program ANR-11-IDEX-0002-02, reference ANR-10-LABX-0037-NEXT. Part of the work has been supported by TERASPEC grant within IDEX Emergence program of University of Toulouse. Zhuo Yang and Nan Zhang hold a fellowship from the Chinese Scholarship Council (CSC). This work was supported by EPSRC (UK) via its membership to the EMFL (grant no. EP/N01085X/1). M. A. J. gratefully acknowledges Cambridge Materials Limited for a PhD scholarship
From Low-Temperature to High-Temperature Phase Exciton Binding Energy and Band Gap Evaluation of CH3NH3PbI3 and CH3NH3PbI3-xClx Perovskites
Full Device photoluminescence and electroluminescence imaging of organic-inorganic perovskite solar cells
Publisher's Note: Electro- and photoluminescence imaging as fast screening technique of the layer uniformity and device degradation in planar perovskite solar cells [J. Appl. Phys. 120
Nucleation and Growth Control of HC(NH<sub>2</sub>)<sub>2</sub>PbI<sub>3</sub> for Planar Perovskite Solar Cell
HCÂ(NH<sub>2</sub>)<sub>2</sub>PbI<sub>3</sub> perovskite solar
cells have emerged as a promising alternative to CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> perovskite solar cells due to their better
thermal stability and lower bandgap. In this work, we have demonstrated
a reliable fabrication technique for HCÂ(NH<sub>2</sub>)<sub>2</sub>PbI<sub>3</sub> planar perovskite solar cells by controlling nucleation
and crystallization processes of the perovskite layer through a combination
of gas-assisted spin coating and the addition of HI additive in the
perovskite precursor. A narrow distribution of power conversion efficiencies
(PCEs) can be achieved with an average of 13% with negligible hysteresis
when measured at a scanning rate of 0.1 V/s. The best performance
device has a PCE of 16.0%. It is shown that by using optimized conditions
we can consistently form dense, uniform, pinhole-free good crystalline,
lead-iodide-impurities-free HCÂ(NH<sub>2</sub>)<sub>2</sub>PbI<sub>3</sub> film that has been comprehensively characterized by scanning
electron microscopy, X-ray diffraction, Kelvin probe force microscopy,
photoluminescence, and electroluminescence in this work