Perovskite Interlayers For Mass Manufacture Using Roll-To-Roll Compatible Deposition Methods

Organic-inorganic perovskites have been used as the light absorbing layer in solar cells since 2009 and have since seen a ground breaking rise in efficiency in a relatively short period of time. Today, perovskite based solar cells have reached efficiencies of over 24% making them a potential competitor to conventional solar cells such as silicon. However, unlike silicon, per-ovskites can essentially be "printed" as the layers can all be solution processed and prepared at low temperatures, giving them a huge advantage in terms of cost and process-ability. Nonethe-less, before perovskites are commercially viable, significant work must be undertaken to ensure they are ready for mass manufacture. This work was aimed at developing large scale compat-ible (roll-to-roll), flexible perovskite solar cells utilising an Indium doped Tin Oxide (ITO) coated PET substrate. Due to the nature of the substrate, the processing temperatures of each layer had to be low and ideally less than 150 °C. Significant work has been undertaken to make perovskite layers roll-to-roll compatible, but the interlayers which it is sandwiched between require further investigation. Therefore, the following work presents the development and ap-plication of a roll-to-roll compatible electron transport layer (ETL) and hole transport layer (HTL). For the deposition of each layer in a roll-to-roll setting, slot-die coating was employed due to its compatibility with solution deposition and small material wastage. In addition, care was taken to focus on low-toxicity alternatives removing barriers that would otherwise be in place for toxic substances which would hinder large scale manufacturing from a health and safety point of view.