Fig. 2

Electronic structure and optical properties of colloidal quantum wells. a Absorption spectrum of a 6.5 ML CQW with specific interband absorption resonances labeled according to the inset cartoon band diagram. b Thickness-dependent energies, in green circles, of the energy experimental difference between energy \({E}\left[ {{\mathrm{HH}}_2 \to {E}_2} \right]\) and the energy \({E}\left[ {{\mathrm{HH}}_2 \to {E}_1} \right]\) of the n = 2 and n = 1 interband transitions, determined from optical absorption spectra. Transition energies are estimated based on analysis of the relevant second derivative minima of the absorption spectra, with errors estimated from the spectral bandwidth of the measurement (~1.5 nm). Also plotted in red squares are experimentally observed intersubband absorptions. The error bars of the photoinduced absorption feature reflect the full-width at half-maximum