Process and material modification study on carbon-based mesoscopic perovskite solar cell performance
Lee, Rainer Cheow Siong
Date of Issue2016-08-03
School of Materials Science and Engineering
Perovskite research have been progressing by leaps and bounds since 2012 with cells already reaching 3/5 of the Shockley–Queisser limit in just 4 years. However, many issues still exist as the active areas of these cells are tiny at around 0.16 cm2, nowhere near the size needed for perovskite cells to be elevated to everyday ubiquity, additionally the high cost and poor stability of the some of the layer materials used in the perovskite cell hinder their viability in cost effective and long term solar energy generation. The use of a carbon based mesoscopic perovskite solar cell eliminates some of these issues as it harnesses the ambipolar nature of perovskite to reduce and/or eliminate the need for a HTM layer, significantly lowering the cost of fabrication while also opening up a path for larger area cells, bringing us ever closer to the crossing the gap from academia to commercial and into mass production. While the perovskite deposition process is already well understood and optimized around the one-step and two-step methods. Many possibilities to modify such processes and the various cell layer materials in order to enhance device performance still exist as can be evidenced by the numerous variations employed by the latest perovskite research papers. The main objective of this work is to explore what modifications can be done in order to enhance the device performance in i) the perovskite deposition process i.e. the one-step (addition of AVAI in perovskite precursor) and the two-step method (addition of Hexane into IPA + MAI solution) and in ii) material modification of a particular cell layer i.e. changing the carbon layer using different conducting paste formulations. The AVAI addition in the perovskite precursor reaffirmed the benefits of using AVAI to template and drive perovskite formation. However, the device fabricated using the Hexane + IPA+ MAI approach was inconclusive due to differing outcomes achieved when compared to what was reported. When testing the cells with different carbon electrodes conductivities, it has been observed that along with the conductivity of the carbon layer, the perovskite precursor deposition process is of equal importance as the driving factors of perovskite solar cell efficiencies.
Final Year Project (FYP)
Nanyang Technological University