Nanoscopic morphologies in block copolymer nanorods as templates for atomic-layer deposition of semiconductors

The fabrication of hierarchical one-dimensional semiconductor nanostructures containing structural motifs, such as helices and stacked doughnuts that are similar to unconventional, confinement-induced nanoscopic domain structures of block copolymers (BCP) melts self-assembled in cylindrical nanopores of anodic aluminum oxide (AAO) with appropriate pore diameters, was reported. The mesoporous PS-b-P2VP nanorods were employed as templates for atomic-layer deposition (ALD) of zinc oxide and three morphology types were found in a PS-b-P2VP nanorod with diameter 170 nm. The pitch of the P2VP single helices and the spacing between the circular-cylindrical P2VP doughnuts is found to be approximately 43 nm. Extraction of the PS-b-P2VP with dimethylformamide yields one-dimensional ZnO characterized by hierarchical architectures, which consist of outer ZnO shells encasing tubular ZnO helices and stacked doughnuts as straight ZnO tubes.