Photoluminescence: Local Versus Long‐Range Diffusion Effects of Photoexcited States on Radiative Recombination in Organic–Inorganic Lead Halide Perovskites (Adv. Sci. 9/2015)

Advanced Science Wiley 2:9 (2015) n/a-n/a

Authors:

Milan Vrućinić, Clemens Matthiesen, Aditya Sadhanala, Giorgio Divitini, Stefania Cacovich, Sian E Dutton, Caterina Ducati, Mete Atatüre, Henry Snaith, Richard H Friend, Henning Sirringhaus, Felix Deschler

The Role of Hole Transport between Dyes in Solid-State Dye-Sensitized Solar Cells

The Journal of Physical Chemistry C American Chemical Society (ACS) 119:33 (2015) 18975-18985

Authors:

Davide Moia, Ute B Cappel, Tomas Leijtens, Xiaoe Li, Andrew M Telford, Henry J Snaith, Brian C O’Regan, Jenny Nelson, Piers RF Barnes

The importance of moisture in hybrid lead halide perovskite thin film fabrication

ACS Nano American Chemical Society 9:9 (2015) 9380-9393

Authors:

Giles Eperon, Severin N Habisreutinger, Tomas Leijtens, Bardo J Bruijnaers, Jacobus J van Franeker, Dane W deQuilettes, Sandeep Pathak, Rebecca J Sutton, Giulia Grancini, David S Ginger, Rene AJ Janssen, Annamaria Petrozza, Henry J Snaith

Abstract:

Moisture, in the form of ambient humidity, has a significant impact on methylammonium lead halide perovskite films. In particular, due to the hygroscopic nature of the methylammonium component, moisture plays a significant role during film formation. This issue has so far not been well understood and neither has the impact of moisture on the physical properties of resultant films. Herein, we carry out a comprehensive and well-controlled study of the effect of moisture exposure on methylammonium lead halide perovskite film formation and properties. We find that films formed in higher humidity atmospheres have a less continuous morphology but significantly improved photoluminescence, and that film formation is faster. In photovoltaic devices, we find that exposure to moisture, either in the precursor solution or in the atmosphere during formation, results in significantly improved open-circuit voltages and hence overall device performance. We then find that by post-treating dry films with moisture exposure, we can enhance photovoltaic performance and photoluminescence in a similar way. The enhanced photoluminescence and open-circuit voltage imply that the material quality is improved in films that have been exposed to moisture. We determine that this improvement stems from a reduction in trap density in the films, which we postulate to be due to the partial solvation of the methylammonium component and “self-healing” of the perovskite lattice. This work highlights the importance of controlled moisture exposure when fabricating high-performance perovskite devices and provides guidelines for the optimum environment for fabrication. Moreover, we note that often an unintentional water exposure is likely responsible for the high performance of solar cells produced in some laboratories, whereas careful synthesis and fabrication in a dry environment will lead to lower-performing devices.

Plasmonic-Induced Photon Recycling in Metal Halide Perovskite Solar Cells

Advanced Functional Materials 25:31 (2015) 5038-5046

Authors:

M Saliba, W Zhang, VM Burlakov, SD Stranks, Y Sun, JM Ball, MB Johnston, A Goriely, U Wiesner, HJ Snaith

Abstract:

Organic-inorganic metal halide perovskite solar cells have emerged in the past few years to promise highly efficient photovoltaic devices at low costs. Here, temperature-sensitive core-shell Ag@TiO2 nanoparticles are successfully incorporated into perovskite solar cells through a lowerature processing route, boosting the measured device efficiencies up to 16.3%. Experimental evidence is shown and a theoretical model is developed which predicts that the presence of highly polarizable nanoparticles enhances the radiative decay of excitons and increases the reabsorption of emitted radiation, representing a novel photon recycling scheme. The work elucidates the complicated subtle interactions between light and matter in plasmonic photovoltaic composites. Photonic and plasmonic schemes such as this may help to move highly efficient perovskite solar cells closer to the theoretical limiting efficiencies.

Plasmonic-induced photon recycling in metal halide perovskite solar cells

Advanced Functional Materials Wiley 25:31 (2015) 5038-5046

Authors:

M Saliba, W Zhang, Victor Burlakov, Michael Johnston, Alain Goriely, Henry Snaith, Et al.

Abstract:

Organic–inorganic metal halide perovskite solar cells have emerged in the past few years to promise highly effi cient photovoltaic devices at low costs. Here, temperature-sensitive core–shell Ag@TiO 2 nanoparticles are successfully incorporated into perovskite solar cells through a low-temperature processing route, boosting the measured device efficiencies up to 16.3%. Experimental evidence is shown and a theoretical model is developed which predicts that the presence of highly polarizable nanoparticles enhances the radiative decay of excitons and increases the reabsorption of emitted radiation, representing a novel photon recycling scheme. The work elucidates the complicated subtle interactions between light and matter in plasmonic photovoltaic composites. Photonic and plasmonic schemes such as this may help to move highly efficient perovskite solar cells closer to the theoretical limiting efficiencies.