Abstract
A facile, low cost, and vacuum free method for fabricating vertically aligned copper indium diselenide (CuInSe 2 ) nanorod (NR) arrays from pre-synthesized CuInSe 2 nanoparticles (NPs) by mechanical approach using porous anodic aluminum oxide (AAO) as a template was demonstrated. This approach utilizes a rubbing technique to fill CuInSe 2 NPs suspension into AAO template. X-ray diffraction and Raman spectroscopy study is employed to confirm the phase of CuInSe 2 NPs before and after the formation of NRs. The polycrystallinity and composition of NRs are confirmed by using transmission electron microscopy. Optical studies of CuInSe 2 NPs film reveal a reflectance of ∼9.8% while a significant reduction of the reflectance to ∼1.2% is observed after the formation of CuInSe 2 NR arrays. The observed low reflectance behavior is attributed to a concept of gradual refractive index with vertical array structures. From differential reflectance spectra of CuInSe 2 NRs, a band gap of ∼1.01 eV was observed, which is identical to its bulk value. © 2012 Elsevier B.V. All rights reserved.