Vapour Deposition of Perovskite Solar Cells
Increasing world needs for electrical power have intensified research into materials suitable for cheap and efficient solar cells. To the great surprise of the photovoltaics community, a new generation of thin-film photovoltaic cells based on organometal trihalide Perovskite absorbers emerged suddenly over the last 2-3 years which rapidly reached power conversion efficiencies now approaching those of silicon solar cells. The methylammonium lead trihalide Perovskite materials absorb broadly across the solar spectrum, making them an exciting new component for low cost clean energy generation. Vapour deposition offers a number of advantages for Perovskite solar cells over the more common solution process approach, including very high uniformity, large-area coverage, and the ability to easily create multilayer devices. Recently we demonstrated highly efficient planar heterojunction solar cells using a dual source vapour deposition method which now opens many new possibilities of device development. In addition we have also recently developed a rapid solar cell characterisation technology that will speed-up the development of Perovskite solar cells by providing very rapid feedback on device performance. The new Fourier Solar Simulator method allows one instrument to be used for the fast measurement of solar cell figures of merit including: (i) total solar-to electrical power conversion efficiency (ii) open circuit voltage Voc (iii) short circuit current Jsc (iv) external quantum efficiency (EQE) (v) internal quantum efficiency (IQE) (vi) maximum power point EQE and IPCE spectra and (vii) a spectral mismatch parameter. This project combines new methodologies of vapour deposition with a new rapid characterisation tool in order to develop high efficiency and stable Perovskite solar cells.