Vertically aligned CuInSe2 nanowire arrays on titanium coated glass substrates for photovoltaic applications

Nanowire arrays of copper indium diselenide (CuInSe₂) were fabricated using an electrochemical deposition process. Custom anodized aluminum oxide (AAO) membranes on a glass substrate with a Ti interlayer served as templates for this electrodeposition. Typical diameter of electrodeposited nanowires was 60 nm although process parameters for anodization could be varied in a controlled way to obtain pore diameters as low as 20 nm. Elemental composition of these CuInSe₂ nanowires on titanium substrate was studied using energy dispersive x-ray analysis (EDX). The atomic percentage ratio for as deposited nanowires was Cu: In: Se= 1:1.16:2.53. The electrolyte composition and other deposition parameters were optimized in order to yield slightly In-rich structures because it is well known that such films result in better photovoltaic devices. It is thought that, with material properties ideally suited for photovoltaic (PV) applications, the use of CIS nanowire arrays would enable a new generation of PV device architectures.