posted on 2023-11-27, 17:05authored byDanila Quarta, Stefano Toso, Antonio Fieramosca, Lorenzo Dominici, Rocco Caliandro, Anna Moliterni, David Maria Tobaldi, Gabriele Saleh, Irina Gushchina, Rosaria Brescia, Mirko Prato, Ivan Infante, Adriano Cola, Cinzia Giannini, Liberato Manna, Giuseppe Gigli, Carlo Giansante
Heavy pnictogen chalcohalide semiconductors are coming
under the
spotlight for energy conversion applications. Here we present the
colloidal synthesis of phase pure AgBiSCl2 nanocrystals.
This quaternary chalcohalide compound features a quasi-two-dimensional
crystal structure and a direct band gap, in contrast with the monodimensional
structure and the indirect band gap peculiar to the orthorhombic,
ternary Bi chalcohalides. Consistently, colloidal AgBiSCl2 nanocrystals exhibit photoinduced luminescence compatible with both
band edge excitons and midgap states. This is the first observation
of band edge emission in chalcohalide nanomaterials at large, although
exciton recombination in our AgBiSCl2 nanocrystals mostly
occurs via nonradiative pathways. This work further advances our knowledge
on this class of mixed anion semiconductor nanomaterials and provides
a contribution to establishing chalcohalides as a reliable alternative
to metal chalcogenides and halides.