Enabling Large Scale Manufacture and Processing of Perovskite Solar cells on Semiconducting Glass Substrates
Authors:   , Smith Benjamin J. 
Published: September 2022

It has been a decade since the initial breakthrough of perovskite solar cells in 2009 and their rise has been nothing short of extraordinary. Power conversion efficiencies have swollen to over 25 % for a single junctioned device. The multitude of different material sets, and applications seem almost limitless. Their relative low cost to manufacture complements an already existing array of PV technologies while offering an alternative route to decarbonising the earth. If the world is ever to meet a net zero emissions, we will need as many renewable sources of energy available as possible. However, perovskite solar cells are still in their relative infancy in terms of commercialisation when compared to more established PV technologies. There are still issues surrounding the large-scale manufacture of long-term stable perovskite solar cells for the commercial market and these issues will need to be addressed sooner rather than later. In this body of work, we identify two existing semiconducting glass substrates from the sponsoring company NSG Pilkington that are currently mass produced for window applications. Remarkably, Eclipse AdvantageTM and TEC15-D were fabricated into highly efficient and stable perovskite solar cells and displayed a remarkable suitability for use within a mass manufactured perovskite solar cell. With the long-term aim of the project to produce a semi-transparent solar window capable of generating its own electricity, the second phase of the project was to engineer perovskites, based on TiO2 and SnO2 respectively, that have the capability to absorb light bifacially or from every direction. We present 2 completely different systems engineered to potentially solve this problem. The first was a novel concept to combine silver nanowires and single walled carbon nanotubes to act as a highly transparent conductive top contact for perovskite solar cells. This composite adheres extremely well to smooth surfaces, something that conventional transparent conductive contacts using metal nanowires struggle with. The method involves no vacuum, is room temperature processed and deposited via a simple and scalable spray processing method that is able to generate power conversion efficiencies of over 11% compared to 16% for opaque evaporated metal contact control devices. The second system involves using a bilayer of IZO and MoOx to encapsulate SnO2 based cells and enhance long term stability while maintaining a high optical transmission and low sheet resistance. By varying the amount of MoOx used to protect softer underlying layers from the sputtering damage of the IZO material we were able to produce cells that maintained and even improved upon initial efficiencies by over 70 % over the course of 700 + hours illumination. The MoOx also allows for the ability to tune the perovskites overall colour, something that must be considered for commercial applications. With these developments a semi-transparent solar window capable of generating its own electricity isn’t far away. In terms of commercialisation, TEC15-D and the bilayer of IZO and MoOx would be most advantageous of all the developments presented within this thesis owing to their ability to be produced at scale and displaying good long-term stability.