Conformal coating of conductive ZnO:Al films as transparent electrodes on high aspect ratio Si microrods

Al-doped ZnO (AZO) thin films were grown by atomic layer deposition (ALD) for use as transparent conductive oxides on high aspect ratio Si microrod arrays. The ALD-deposited AZO films showed high optical transmittance and electrical conductivity despite their polycrystalline structures and resulted in a superior conformal coating on the surface and side regions of the Si microrods. The films also exhibited an electrical performance identical to that of the AZO film on a flat Si substrate. These results revealed that ALD-deposited AZO films are promising candidates for electrodes in the next-generation optoelectronic devices based on low dimensional structures, which require conformal coating.