Enhanced Amplified Spontaneous Emission in Perovskites Using a Flexible Cholesteric Liquid Crystal Reflector
- 31 July 2015
- journal article
- research article
- Published by American Chemical Society (ACS) in Nano Letters
- Vol. 15 (8), 4935-4941
- https://doi.org/10.1021/acs.nanolett.5b00678
Abstract
Organic-inorganic perovskites are highly promising solar cell materials with laboratory-based power conversion efficiencies already matching those of established thin film technologies. Their exceptional photovoltaic performance is in part attributed to the presence of efficient radiative recombination pathways, thereby opening up the possibility of efficient light-emitting devices. Here, we demonstrate optically pumped amplified spontaneous emission (ASE) at 780 urn from a 50 nm-thick film of CH3NH3PbI3 perovskite that is sandwiched within a cavity composed of a thin-film (similar to 7 mu m) cholesteric liquid crystal (CLC) reflector and a metal back-reflector. The threshold fluence for ASE in the perovskite film is reduced by at least two orders of magnitude in the presence of the CLC reflector, which results in a factor of two reduction in threshold fluence compared to previous reports. We consider this to be due to improved coupling of the oblique and out-of-plane modes that are reflected into the bulk in addition to any contributions from cavity modes. Furthermore, we also demonstrate enhanced ASE on flexible reflectors and discuss how improvements in the quality factor and reflectivity of the CLC layers could lead to single-mode lasing using CLC reflectors. Our work opens up the possibility of fabricating widely wavelength-tunable "mirror-less" single-mode lasers on flexible substrates, which could find use in applications such as flexible displays and friend or foe identification.Funding Information
- Merck
- University of Cambridge
- Seventh Framework Programme (604032)
- Engineering and Physical Sciences Research Council
- Dutch Polymer Institute (764)
- Royal Society
This publication has 56 references indexed in Scilit:
- Lead Iodide Perovskite Sensitized All-Solid-State Submicron Thin Film Mesoscopic Solar Cell with Efficiency Exceeding 9%Scientific Reports, 2012
- Liquid-crystal lasersNature Photonics, 2010
- Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic CellsJournal of the American Chemical Society, 2009
- Optical cavity with a double-layered cholesteric liquid crystal mirror and its prospective application to solid state laserApplied Physics Letters, 2006
- Electroluminescence from an Organic−Inorganic Perovskite Incorporating a Quaterthiophene Dye within Lead Halide Perovskite LayersChemistry of Materials, 1999
- Photo-Induced Diffusion in Polymerizing Chiral-Nematic MediaAdvanced Materials, 1999
- Spectral narrowing in optically pumped poly (p‐phenylenevinylene) FilmsAdvanced Materials, 1997
- Wide-band reflective polarizers from cholesteric polymer networks with a pitch gradientNature, 1995
- Peak reflectance and color gamut of superimposed left- and right-handed cholesteric liquid crystalsApplied Optics, 1980
- Optics in Stratified and Anisotropic Media: 4×4-Matrix FormulationJournal of the Optical Society of America, 1972