A method of forming a crosslinked, non-discotic backbone polymer coating on a substrate, comprises the steps of: (a) coupling a layer of porphyrinic macrocycles to the substrate; (b) cross-linking the layer of porphyrinic macrocycles to form a layer of cross-linked porphyrinic macrocycles; and then (c) coupling a subsequent layer of porphyrinic macrocycles to the layer of cross-linked porphyrinic macrocycles of step (b) to form a non-discotic backbone polymer of porphyrinic macrocycles between the cross linked layer of step (b) and the subsequent layer of porphyrinic macrocycles to form a crosslinked, non-discotic backbone polymer coating thereon. Light harvesting arrays and solar cells that can be produced by such methods are also described.