Photoluminescence as a Quantitative Probe of Semiconductor Nanocrystals

Photoluminescence spectroscopy is among the most established characterization techniques for semiconductor nanocrystals, yet routine analysis is often limited to the emission peak position and full width at half-maximum. Here, we identify a common statistical structure in ensemble photoluminescence and introduce a Gaussian asymmetric Laplace (GaLa) framework that transforms this structure into quantitative information about the emissive ensemble. The model describes emission as the convolution of a Gaussian contribution with independent low- and high-energy spectral tails. Temperature-dependent measurements reveal distinct thermal evolution of these contributions, while the same statistical form captures diverse nanocrystal compositions, morphologies, and environments. Where an appropriate size–energy relationship is available, the Gaussian width can be mapped onto relative size dispersion, while systematic deviations expose hidden emissive subpopulations. Applied during CsPbBr3 nanocube syntheses, GaLa analysis simultaneously tracks nanocrystal growth and ensemble focusing, establishing routine photoluminescence as a quantitative probe of nanocrystal ensembles.