Optoelectronic properties of metal halide perovskites with varying dimensionality

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Project description including a brief statement on how it aligns with EPSRC strategy/priority research areas:Metal halide perovskites have made a remarkably successful entry into the field of next-generation photovoltaic cells with certified power conversion efficiencies now exceeding 26% for single-junction thin-film solar cells. While competing technologies currently exist for such devices, the world's growing need for energy supply, lighting and display technologies has created an increasing desire for low-cost, high-efficiency solutions. Continued advances in photovoltaic devices, are urgently required to address climate change and energy security, which are arguably the greatest challenges to be faced by mankind over the coming century. In parallel, optoelectronic properties leading to light emission from these materials are being explored, which have promises to deliver lighting applications with high efficiency and low energy usage.This EPSRC DTP Studentship will focus on exploring key optoelectronic properties of metal halide perovskites with a range of different dimensionalities, in order to probe both fundamental effects such as quantum confinement, and application-driven performance parameters. Metal halide semiconductors will be explored with a range of different structural and electronic dimensionalities, including quasi-zero-dimensional colloidal quantum dots and two-dimensional quantum wells. For the latter, in particular, lattice-matching with substrates will be explored for growth of ultra-thin layers of perovskites that may exhibit quantum confinement effects. Fundamental optoelectronic properties will be elucidated, focussing on how quantum confinement affects mechanisms for excitonic effects, electron-phonon coupling, charge-carrier mobility and recombination, light emission and re-absorption. Materials will be explored using a combination of ultra-fast optical techniques, e.g. transient absorption, photoluminescence up-conversion and THz pump-probe spectroscopy, while basic optical and structural properties will be examined with Fourier-transform infrared spectroscopy, x-ray diffraction and electron microscopies. These studies will feed directly into collaborative efforts aimed at propelling forward the growth of low-dimensionality perovskites, and their ultimate use in light-emitting and -harvesting applications.The proposed research clearly fits within the EPSRC's portfolio, targeting identified Grand Challenges in Physics (Nanoscale Design of Functional Materials) and Chemistry (Directed Assembly of Extended Structures with Targeted Properties). The proposed programme also clearly falls into the EPSRC Themes of Physical Sciences, Energy & Manufacturing the Future; and the Areas of Materials for Energy Applications, Computational and Theoretical Chemistry and Solar Technology.