Metal hAlide perovSkiTE single crystals for solaR cells

Photovoltaic (PV) solar energy conversion to electricity is growing as the most significant player in the transition to renewable
energy. The lowering of the cost of established technologies, like silicon and cadmium telluride, and the development of new
promising materials is providing more and more effective solutions to attract investments in the PV field. Recently, metal halide
perovskites (PVKs) have demonstrated a clear potential as new materials for high-efficiency solar cells. Solution processing and
thermal vacuum deposition are the most common methods adopted to achieve uniform perovskite films with a smooth surface on a
large area, at the moment. The advancement in device efficiency is often ascribed to the progress in controlling the polycrystalline
film formation and reducing the occurrence of morphological defects such as pinholes. However, polycrystalline perovskite films can
still suffer from chemical defects, mostly linked to grain boundaries’ unavoidable presence. In the MASTER project, we propose the
development of PV devices based on perovskite single crystals (PVK-SCs). The proposal follows the path of silicon PVs that has
improved reliability and efficiency moving from polycrystalline to single crystal cells, as well as the general technological path of
optoelectronic devices that thrive when intrinsic, crystalline semiconductors are employed. PVK-SCs have the potential to boost both
PV performance and stability, thanks to lower trap state densities, higher carrier mobilities, and longer diffusion lengths. Challenges
related with PVK-SC growth remains, namely obtaining a compositional gradient and finding a method that would allow simultaneous
control over the lateral dimensions and thicknesses; these latter is a prerequisite for the effective integration into a complete solar
cell device stack. In the MASTER project we will develop the geometrically-controlled growth of PVK-SCs and tackle their integration
in the actual solar cell architecture. High-quality PVK-SCs, benchmark lead (Pb)- and lead-free-tin (Sn)- based compositions will be
grown by means of a micro-structured polydimethylsiloxane (PDMS) mould, obtained via soft-lithography. The conformability,
chemical inertness and ease of functionalization of PDMS will be exploited to geometrically confine the precursors’ solutions and act
on the growth of high-quality PVK-SCs directly onto arbitrary substrates. The ultimate goal of the project is to master the
preparation of PVK-SC materials and devices, first by understanding its physical-chemical properties and, finally,
integration of PVK-SCs in the actual solar cell devices.
The team comprises research units that are worldwide front runners of PVK-based optoelectronics and the present proposal
represents the opportunity of creating significant synergy and kick start a next generation solar conversion Italian hub based in the
south.