The societal appetite for green and clean technology, which should be innovative and cost-effective are increasing. This allowed us to investigate innovative materials, which can convert sun rays into electricity at cut rate price. MOLEMAT is a multidisciplinary project and addresses different area of expertise such as synthetic chemistry, materials science, electro-optical characterization and device fabrication. MOLEMAT contributes to the competitiveness of the European photovoltaic based industry, contributing to the tree of knowledge, designing efficient materials, creates know how and trained new generation of materials scientists.
The societal need to fulfil the energy demand of our planet is a pressing issue and considerable efforts are being made to find decarbonized process for energy conversion. The overarching aim of the project was the development of high performance materials, process identification to promote photovoltaic (PV) properties. Silicon based solar cells utilizes around 200 microns thick layer in order to effectively capture light, while perovskites are exceptionally strong light absorbers and can absorb the same amount of light with a thickness of only 0.5 microns. Thus the cost of active materials is just a couple of euros per square meter, and the PV panel will costs half as compared to the current technology, while also does not demand high capital cost due to its solution processing.
Perovskite based solar cell, as emerged as strong contender in thin film PV technology as it offers to harvest light at grid parity, currently >26% light to electricity, power conversion efficiencies (PCEs), are being measured, which has well positioned it at par with mature thin film PV technologies.[i] Further push in PCE and stability requires new approaches, to ultimately enable this technology ready for manufacturing. The main objectives achieved in this project is a) design materials by engineering at a molecular level for p-type and n-type charge collection, adding functionality to the perovskites and b) to find a process for large area deposition to promote photovoltaic properties. For perovskite formation, we made powder engineering, compositional engineering to enhance the stability and absorption onset, crystal size control (anti-solvent approach), optimized thickness, doping.
Despite commendable efforts, pure FAPI perovskite thin film is prone to critical phase-transition issues due to its thermodynamically stable non-perovskite phase (2H). We reported a rational additivization strategy to overcome this challenge with the help of multifunctional ammonium salt containing a sulfur heteroatom that shifts the thermodynamic stability from the 2H phase to an intermediate phase closer to the cubic phase, and it showed damp and water stability in pure formamidinium lead triiodide.
