Publication date: 17th February 2025
The photoactive α-phase of formamidinium lead triiodide (α-FAPbI3) is thermodynamically unstable under ambient conditions, limiting its use in perovskite solar cells. However, tilting of the [PbI6] octahedra comprising the cubic α-FAPbI3 structure increases resistance to its transformation into the photoinactive 2H-phase. This tilting is typically induced by substituting FA+ or I- for Cs+, methylammonium, or Br-. However, such substitutions increase the semiconductor bandgap and risk halide or cation segregation, leading to formation of local FAPbI3-rich regions that rapidly transform to the undesirable 2H-phase. To demonstrate this, we compare β-alanine and L-arginine addition to FAPbI3 precursor solutions using liquid state nuclear magnetic resonance (NMR) spectroscopy and find that: (a) both additives undergo in-situ reaction with FA+ which makes the effective additive chemically different than the pristine additives, and (b) this solution chemistry inhibits zwitterion formation in β-alanine, but not in L-arginine. After reaction L-arginine retains its zwitterionic form and therefore its carboxylate (COO-) functionality, which is key to its α-FAPbI3 stabilization activity. This enables COO--Pb2+ interactions in solution, which we show using solid-state NMR are preserved into the solid thin films and are critical for inducing octahedral tilt in α-FAPbI3 thin films fabricated in the presence of L-arginine, and therefore α-phase stabilization. Consequently, such films exhibit over 1,000 hours of photoactive phase stability under ambient conditions. Using nano infra-red mapping, we show that incorporated L-arginine is concentrated at the domain boundaries of α-FAPbI3 thin films, indicating perovskite phase surface-binding and consistent with additive-templated octahedral tilting.
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.