A detailed discussion of this analytical model and a copy of the MATLAB script that runs the fitting procedure can be found in reference 38. To summarize, the HEDA model uses four input values obtained from experimental data, volume fraction of NCs in the dispersion 𝑓 𝑣 , the average diameter 𝜇 𝑟 , and the standard deviation in diameter 𝜎 𝑟 , along with an experimental extinction spectrum of a dilute solution of NCs. From this, the HEDA model fits for four optoelectronic variables, the average electron concentration 𝑛 𝑒 , the standard deviation in a normal distribution of charge electron concentrations 𝜎 𝑛 𝑒 , the mean free path of a charge electron 𝑙 𝑀𝐹𝑃 , and the electron accessible volume fraction 𝑓 𝑒 . The model accounts for heterogeneity, unlike the simple Drude approximation, by considering distributions in the size and electron concentration. Additionally, the depletion layer and surface scattering are considered in the optical response to improve upon the Drude approximation. A successful fitting procedure enables the determination of the properties of an average NC in an ensemble, unclouded by the effects of heterogeneity.