Large lattice distortions and size-dependent bandgap modulation in epitaxial halide perovskite nanowires

Metal-halide perovskites are promising photovoltaic materials, but fundamental questions remain open due to their structural complexity. Here the authors show, by correlated microscopy and spectroscopy methods, that epitaxially induced lattice distortions drive a size dependent modulation of the bandgap in a homogeneous nanowire system.