posted on 2021-06-03, 20:44authored byElena Blundo, Antonio Polimeni, Daniele Meggiolaro, Andrea D’Annibale, Lorenza Romagnoli, Marco Felici, Alessandro Latini
Lead halide perovskites
are outstanding materials for optoelectronics,
but they typically feature low stability against external agents.
To overcome this drawback, LHPs based on quaternary ammonium cations,
such as phenyl viologen lead iodide (PhVPI), were found to be promising
candidates, being water-resistant and thermally stable. In this Letter,
the optoelectronic properties of the PhVPI are investigated by a combined
experimental–theoretical approach. Although the as-prepared
material is photoluminescence-inactive, a short thermal (5 min @ 290
°C) or laser annealing turns PhVPI into a highly luminescent
material, in the 600–1000 nm range. The PhVPI PL emission was
characterized at different annealing conditions, and the structural
evolution following thermal treatments was investigated by means of
X-ray diffraction, Raman, and NMR spectroscopies. Besides this, the
electronic structure and emission properties were investigated by
density functional theory simulations. The intense optical emission
and high stability make PhVPI an intriguing material for applications
related to light-emitting devices.