journal homepage: www.elsevier.com/locate/nanoenergy Available online at www.sciencedirect.com RAPID COMMUNICATION Geometrical control of photocurrent in active Si nanowire devices Amit Solanki a,n , Pascal Gentile a , Vincent Calvo a , Guillaume Rosaz a,b , Bassem Salem b , Vincent Aimez c , Dominique Drouin c , Nicolas Pauc a a SiNaPS/SP2M, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble F-38054, France b Laboratoire des Technologies de la Micro  electronique, CNRS, Grenoble, France c Centre de recherche en nanofabrication et nanocaract  erisation, Universit  e de Sherbrooke, Qu  ebec, Canada Received 1 March 2012; received in revised form 23 May 2012; accepted 23 May 2012 KEYWORDS Nanowires; Absorption; Photocurrent; Photovoltaic devices; Mie resonance; EBIC Summary The growing research in the field of photovoltaics has led to various strategies for increasing the light interaction in absorbers, for instance the use of nanostructures like nanowires where leaky mode resonances enhanced absorption efficiency. Towards this goal, we present a study of the light absorption in single Si nanowires, by means of microphotocurrent spectroscopy combined with transport measurements of carrier diffusion length using the electron beam induced current technique. The study is performed on different diameter nanowires with Schottky junctions created by doping modulation during Chemical Vapor Deposition–Vapor Liquid Solid growth. We show that the photocurrent spectra of single Si nanowires do not follow monotonous profiles as bulk silicon, but rather have steep valleys and peaks whose position and intensity are diameter dependent. These sharp modulations result from a resonant coupling between incident photons and cavity modes of the nanowires. A good agreement between the experiment and the theoretical fit using Mie theory is observed with a red shift in the absorption spectrum with increasing diameters. & 2012 Elsevier Ltd. All rights reserved. Introduction NWs have been extensively studied for their novel proper- ties which encompass their application in future electronics [1–5], photonics [6], thermoelectric [7,8], sensors [9,10], etc. One field of immense potential is energy sector where new routes are being unraveled to fuel the future of the world energy consumption [11,12]. The tremendous growth in the photovoltaics in last few years has led to great deal of 2211-2855/$ - see front matter & 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.nanoen.2012.05.010 Abbreviations: NW, nanowire; EBIC, Electron Beam Induced Current; I–V , current–voltage; CVD, Chemical Vapor Deposition; VLS, Vapor Liquid Solid n Corresponding author. Tel.: +33 4 38 78 18 06; fax: + 33 4 38 78 58 17. E-mail address: amit.solanki@cea.fr (A. Solanki). Nano Energy (]]]]) ], ]]]–]]] Please cite this article as: A. Solanki, et al., Geometrical control of photocurrent in active Si nanowire devices, Nano Energy (2012), http: //dx.doi.org/10.1016/j.nanoen.2012.05.010