title: Tunable antireflection from conformal Al-doped ZnO films on nanofaceted Si templates.
abstract: Photon harvesting by reducing reflection loss is the basis of photovoltaic devices. Here, we show the efficacy of Al-doped ZnO (AZO) overlayer on ion beam-synthesized nanofaceted silicon for suppressing reflection loss. In particular, we demonstrate thickness-dependent tunable antireflection (AR) from conformally grown AZO layer, showing a systematic shift in the reflection minima from ultraviolet to visible to near-infrared ranges with increasing thickness. Tunable AR property is understood in light of depth-dependent refractive index of nanofaceted silicon and AZO overlayer. This improved AR property significantly increases the fill factor of such textured heterostructures, which reaches its maximum for 60-nm AZO compared to the ones based on planar silicon. This thickness matches with the one that shows the maximum reduction in surface reflectance.
  81.07.-b; 42.79.Wc; 81.16.Rf; 81.15.Cd.
authors.affiliation: Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005, India.
authors.forename: Tanmoy
authors.initials: T
authors.lastname: Basu
authors.affiliation: Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005, India.
authors.forename: Mohit
authors.initials: M
authors.lastname: Kumar
authors.affiliation: National Institute of Science Education and Research, Sachivalaya Marg, Bhubaneswar 751005, India.
authors.forename: Pratap Kumar
authors.initials: PK
authors.lastname: Sahoo
authors.affiliation: Department of Physics, School of Natural Sciences, Shiv Nadar University, Gautam Budh, Nagar, Uttar Pradesh 203207, India.
authors.forename: Aloke
authors.initials: A
authors.lastname: Kanjilal
authors.affiliation: Institute of Physics, Sachivalaya Marg, Bhubaneswar 751005, India.
authors.forename: Tapobrata
authors.initials: T
authors.lastname: Som
keywords: Aluminum-doped zinc oxide; Antireflection property; Ion beam-induced nanopatterning; Silicon; Sputter deposition