Improving the stability, aesthetics and performance of perovskite materials for photovoltaics

The generation of energy is the most important scientific and technological challenge that faces humankind in the 21st century. In order to supply the demand of increasing global energy requirements, the development of low cost, easily processable, efficient photovoltaics (PV) is essential. Third generation PV offers a potentially low cost, easily processable and efficient technology and before us lays a great opportunity in solar energy research. International progress in PV research and technology is currently running at an unparalleled rate, with major contributions from the SPECIFIC and Ser Solar groups. The extremely rapid evolution of solution processed halide perovskite-based solar cells during the last few years (reaching efficiencies in the range of 15-20%, including certified 20.1%) makes them an extremely strong candidate to develop a cost and performance competitive PV technology. Photovoltaic devices which utilise light harvesting perovskite chemistries could potentially offer a cheaper and simpler technology in comparison to the typically favoured silicon solar cell. However, current issues when using perovskites for PV application include physicochemical degradation, instability and lifetime issues up on exposure to ambient conditions. The fundamental workings and reasoning for the aforementioned problems when using perovskite absorbers are yet to be fully understood. The project is concerned with gaining a better understanding of halide perovskite chemistry through identification and investigation of the manufacturing conditions or parameters which may lead to device instabilities. Fluorescence microscopy and fluorescence spectroscopy are two techniques which will be applied to investigate the photoluminescent properties and morphologies of a range of perovskite materials prepared under different conditions. The project research will explore routes to increasing the efficiency and light harvesting ability of these devices. There is also scope to use X-ray diffraction to investigate the crystalline structure of the perovskite layer and to determine whether the uniformity of this layer (amongst other layers) is affected by the alteration of certain parameters during device manufacture. The degradation of perovskite is believed to be exacerbated due to reaction with oxygen which will be investigated using transient absorption spectroscopy as a method to monitor oxygen diffusion within halide-perovskite solar cells. The overall aim is to develop an understanding of device photophysics and photochemistry resulting in the development of new materials to improve stability and cost and leading to world leading, high impact articles in the premier international journals in the field.