PbSe films with highly periodic nanoscale features were deposited over macroscale areas by utilizing a completely template-free photoelectrochemical deposition technique wherein the nature of the illumination directs the resultant material morphology. Highly-anisotropic lamellae were produced using linearly polarized light and the lamellae were oriented along the polarization axis; the pitch and width of these nanoscale features was observed to scale with the illumination wavelength. The deposition was simulated using a finite-difference time domain method to model light absorption and a Monte Carlo method for mass addition and the results of the simulation successfully reproduced the experimentally observed morphologies. The generation of polycrystalline PbSe was confirmed by energy dispersive X-ray spectroscopy and X-ray diffraction. Complete nanoscale patterning over square centimeter areas required only several minutes. Moreover, films were deposited from aqueous solution using oxidized precursors at room temperature and no lithographic processing or photomasks were utilized nor needed. Thus, this technique offers a method by which nanostructured semiconducting materials can be generated rapidly via a bottom-up approach capitalizing on the self-optimization of the material growth to maximize interfacial light absorption. Extension of this technique to generate other IV-VI as well as II-VI semiconductors is currently being explored.