Si Nanowires Light Absorption Research Conventional paper

Si Nanowires Light Consumption

Nano Strength (2012) 1, 714–722

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Geometrical control of photocurrent in energetic Si nanowire devices Amit Solankia, n, Pascal Gentilea, Vincent Calvoa, Guillaume Rosaza, b, Bassem Salemb, Vincent Aimezc, Dominique Drouinc, Nicolas Pauca SiNaPS/SP2M, UMR-E CEA/UJF-Grenoble 1, INAC, Grenoble F-38054, France Laboratoire des Solutions de la Microelectronique, CNRS, Grenoble, France c Centre de recherche en nanofabrication et nanocaracterisation, Universite para Sherbrooke, Quebec, Canada b a

Received 1 03 2012; received in revised form twenty-three May 2012; accepted 3 May 2012 Available online two June 2012

KEYWORDS

Nanowires; Absorption; Photocurrent; Photovoltaic equipment; Mie reverberation; EBIC

Overview

The developing research inside the field of photovoltaics has resulted in various strategies for increasing the light interaction in absorbers, for example the use of nanostructures like nanowires where leaking mode resonances enhanced absorption efficiency. Towards this target, we present a study from the light compression in single Si nanowires, by means of microphotocurrent spectroscopy along with transport measurements of company diffusion length using the electron beam induced current strategy. The study is performed on different diameter nanowires with Schottky junctions made by doping modulation during Chemical Vapor Deposition–Vapor The liquid Solid development. We demonstrate that the photocurrent spectra of single Dans le cas ou nanowires tend not to follow boring profiles as bulk silicon, but rather have got steep valleys and highs whose position and strength are size dependent. These kinds of sharp modulations result from a resonant coupling between episode photons and cavity ways of the nanowires. A good agreement between the experiment and the theoretical fit using Mie theory is noticed with a crimson shift in the absorption spectrum with elevating diameters. & 2012 Elsevier Ltd. Every rights set aside.

Introduction

Short-hand: NW, nanowire; EBIC, Electron Beam Induced Current; I–V, current–voltage; CVD, Chemical Water vapor Deposition; VLS, Vapor The liquid Solid d Corresponding publisher. Tel.: +33 4 35 78 18 06; fernkopie: +33 4 38 79 58 seventeen. E-mail addresses: amit. [email protected] fr (A. Solanki). 2211-2855/$ - observe front subject & 2012 Elsevier Limited. All privileges reserved. http://dx.doi.org/10.1016/j.nanoen.2012.05.010

NWs have been completely extensively examined for their story properties which will encompass their application in future electronics [1–5], photonics [6], thermoelectric [7, 8], sensors [9, 10], etc . One particular field of immense potential is energy sector wherever new ways are staying unraveled to fuel the ongoing future of the world energy consumption [11, 12]. The huge growth in the photovoltaics in last few years has resulted in great deal of

Geometrical control of photocurrent in lively Si NW devices exploration in building and characterizing junction in NWs to achieve a NW array based solar cellular. With current progress the NW arrays with both central and gigantic junction have been studied with efficiencies similar to thin film and large Si solar cells [13, 14]. Learning the single NW electro-optical houses is therefore of critical importance to get the best possible design in the foreseeable future NW mixture based solar cells. In our job, we modulate the doping along the NWs during single VLS growth to obtain p+-intrinsic or d +intrinsic (p +i and n +i respectively) dopant distribution in NWs. In this way, by using same contacts on either area of the nanowire, we fabricate ohmic contact on one side and rectifying contact on the reverse side to obtain effective devices exactly where no external bias is required to generate photocurrent. This approach uses conventional doping methods to generate built in electric powered fields, which can be viewed as an alternate approach to the metal–semiconductor–metal photodetectors made upon intrinsic Ge nanowires [15]. In such a case, the nature of the electrical contact can be fine-tined by...