Unraveling the photoluminescence of inorganic-organic perovskites

Matt Carnie^a, Joel Troughton^a, Cecile Charbonneau^a, Trystan Watson^a, Matthew Davies^a, Dave Worsley^a, Peter Douglas^b

^aSPECIFIC, Swansea University, Baglan Bay Innovation and Knowledge Centre, Baglan, SA12 7AX, United Kingdom

^bChemistry Group, College of Engineering, Swansea University, Singleton Park Swansea, SA2 8PP

International Conference on Hybrid and Organic Photovoltaics
Proceedings of International Conference on Hybrid and Organic Photovoltaics 2015 (HOPV15)

Roma, Italy, 2015 May 11th - 13th

Organizer: Filippo De Angelis

Poster, Matthew Davies, 212
Publication date: 5th February 2015

The remarkable evolution of perovskite-based solar cells during the last 2 years, reaching efficiencies in the range of 15 - 20%,^1,2including certified 20.1%, makes them an extremely strong candidate to develop a low cost, low embodied energy, performance-competitive PV technology. Significant progress has also been made on manufacturing processes and potentially lowering the cost of devices through the replacement of expensive components.^2-4However, stability and lifetime issues, and a detailed understanding of the fundamental workings of perovskite absorbers are yet to be fully understood. Here we report the characteristics of a series of perovskites with various halide combinations studied via fluorescence microscopy (FM) coupled with an optical fibre spectrometer. This provides information on the local photoluminescence (PL) and allows us to map the surface of the films. We have followed the evolution of PL upon crystallisation and subsequent degradation of perovskite films. A number of interesting observations have been made such as different emission wavelengths for single halide perovskites, delayed emission, non-emissive or only weakly emissive crystals. Here we attempt to correlate the PL, crystal size, structure and coverage with overall PV device efficiency. We have studied the effect of annealing temperature and rate of heating on the crystallisation and PL, including the effect of near-infrared heating that we have previously shown to complete the crystallisation of perovskites in around 2 seconds.⁵ As expected the heating profile has a large effect on the crystal structure and stability of the crystallised film. FM has proved to be an easy and efficient way to study and evaluate perovskite films. Complementary techniques including X-ray diffraction and scanning electron microscopy have also been used.
Figure 1. Fluorescence microscopy pictures of tri-bromide (left and centre-left) and tri-iodide (centre–right and right) perovskite crystals. We note that: not all crystals are emissive, various colour domains exist, and there are a range of crystal morphologies, details, which, we believe, will shed insight into the nature of these materials.
1) Zhou, H.; Chen, Q.; Li, G.; Luo, S.; Song, T. -b.; Duan, H.-S.; Hong, Z.; You, J.; Liu, Y.; Yang, Y. Interface engineering of highly efficient perovskite solar cells. Science. 2014, 345, 542–546. 2) Wang, J. T-W.; Ball, J. M.; Barea, E. M.; Abate, A.; Alexander-Webber, J. A.; Huang, J.; Saliba, M.; Mora-Sero, I.; Bisquert, J.; Snaith, H. J.; Nicholas, R. J. Low-Temperature Processed Electron Collection Layers of Graphene/TiO2 Nanocomposites in Thin Film Perovskite Solar Cells. Nano Lett. 2014, 14, 724–730. 3) Bryant, D.; Greenwood, P.; Troughton, J.; Wijdekop, M.; Carnie, M.; Davies, M.; Wojciechowski, K.; Snaith, H. J.; Watson, T.; Worsley, D. A Transparent Conductive Adhesive Laminate Electrode for High-Efficiency Organic-Inorganic Lead Halide Perovskite Solar Cells. Adv. Mater. 2014, 26, 7499-7504. 4) Carnie, M. J.; Charbonneau, C. M. E.; Davies, M. L.; Troughton, J.; Watson, T. M.; Wojciechowski, K.; Snaith, H. J.; Worsley, D. A. A one-step low temperature processing route for organolead halide perovskite solar cells. Chemical Communications 2013, 49, 7893-7895. 5) Troughton, J; Charbonneau, C. M. E.; Carnie, M. J.; Davies, M. L.; Worsley, D. A.; Watson, T. M. Fast annealing of organolead halide perovskite in solar cells. Manuscript in preparation.

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.

MATSUS

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.

International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics

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.