The present invention provides a method of prepg. Al-doped Zn oxide (AZO) nanocrystals. In an exemplary embodiment, the method includes (1) injecting a precursor mixt. of a Zn precursor, an Al precursor, an amine, and a fatty acid in a soln. of a vicinal diol in a noncoordinating solvent, thereby resulting in a reaction mixt., (2) pptg. the nanocrystals from the reaction mixt., thereby resulting in a final ppt., and (3) dissolving the final ppt. in an apolar solvent. The present invention also provides a dispersion. In an exemplary embodiment, the dispersion includes (1) nanocrystals that are well sepd. from each other, where the nanocrystals are coated with surfactants and (2) an apolar solvent where the nanocrystals are suspended in the apolar solvent. The present invention also provides a film. In an exemplary embodiment, the film includes (1) a substrate and (2) nanocrystals that are evenly distributed on the substrate.