Prof Henry Snaith FRS: Publications

Towards long-term photostability of solid-state dye sensitized solar cells

Advanced Energy Materials 4:8 (2014)

Authors:

SK Pathak, A Abate, T Leijtens, DJ Hollman, J Teuscher, L Pazos, P Docampo, U Steiner, HJ Snaith

Abstract:

The solid-state dye-sensitized solar cell (DSSC) was introduced to overcome inherent manufacturing and instability issues of the electrolyte-based DSSC and progress has been made to deliver high photovoltaic efficiencies at low cost. However, despite 15 years research and development, there still remains no clear demonstration of long-term stability. Here, solid-state DSSCs are subjected to the severe aging conditions of continuous illumination at an elevated temperature. A fast deterioration in performance is observed for devices encapsulated in the absence of oxygen. The photovoltaic performance recovers when re-exposed to air. This reversible behavior is attributed to three related processes: i) the creation of light and oxygen sensitive electronic shunting paths between TiO2 and the top metal electrode, ii) increased recombination at the TiO2/organic interface, and iii) the creation of deep electron traps that reduce the photocurrent. The device deterioration is remedied by the formation of an insulating alumino-silicate shell around the TiO2 nanocrystals, which reduces interfacial recombination, and the introduction of an insulating mesoporous SiO2 buffer layer between the top electrode and TiO2, which acts as a permanent insulating barrier between the TiO2 and the metal electrode, preventing shunting. Encapsulated solid-state dye-sensitized solar cells (ssDSSCs) show a reversible and quick deterioration in performance while aging under inert atmosphere. This is attributed to the activation of deep traps and the change in Schottky barrier at the TiO2 surface. This is remedied by forming an insulating alumino-silicate "shell" around the TiO2 nanocrystals, and by introducing an insulating mesoporous SiO2 "buffer layer" between the top electrode and TiO2. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multiscale Simulation of Solid State Dye Sensitized Solar Cells Including Morphology Effects

Institute of Electrical and Electronics Engineers (IEEE) (2014) 1-4

Authors:

Alessio Gagliardi, Matthias Auf der Maur, Fabio Di Fonzo, Agnese Abrusci, Henry Snaith, Giorgio Divitini, Caterina Ducati, Aldo Di Carlo

Lessons Learned: From Dye‐Sensitized Solar Cells to All‐Solid‐State Hybrid Devices

Advanced Materials Wiley 26:24 (2014) 4013-4030

Authors:

Pablo Docampo, Stefan Guldin, Tomas Leijtens, Nakita K Noel, Ullrich Steiner, Henry J Snaith

Preface

Thin Solid Films Elsevier 560 (2014) 1

Authors:

Annamaria Petrozza, Efrat Lifshitz, Henry Snaith, Cesare Soci

Charge-carrier dynamics in vapour-deposited films of the organolead halide perovskite CH3NH3PbI3-xClx

Energy and Environmental Science Royal Society of Chemistry 7:7 (2014) 2269-2275

Authors:

Christian Wehrenfennig, Mingzhen Liu, Henry J Snaith, Michael J Johnston, Laura M Herz

Abstract:

We determine high charge-carrier mobilities ≥ 33 cm2 V−1 s−1 and bi-molecular recombination rates about five orders of magnitude below the prediction of Langevin's model for vapour-deposited CH3NH3PbI3−xClx using ultrafast THz spectroscopy. At charge-carrier densities below ∼1017 cm−3 intrinsic diffusion lengths are shown to approach 3 microns, limited by slow mono-molecular decay processes.

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