Electrical properties related to the structure of GeSi nanostructured films. Issue 7 (22nd January 2014)

• Record Type: Journal Article
• Authors: Ciurea, Magdalena Lidia; Stavarache, Ionel; Lepadatu, Ana‐Maria; Pasuk, Iuliana; Teodorescu, Valentin Serban
• Is Part Of: Physica status solidi. Volume 251:Issue 7(2014:Jul.)
• Page Start: 1340
• Page End: 1346
• Publication Date: 2014-01-22
• Subjects: Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.201350112
• Languages: English
• ISSNs: 0370-1972

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="pssb201350112-sec-0001" sec-type="section"> <p>GeSi nanostructured films were obtained by cosputtering from two Ge and Si targets and subsequent annealing in furnace in N<sub>2</sub> for 5 h at 700, 800 and 900 °C, with the aim to show the correlation between electrical properties and crystalline structure of the films. The as‐deposited films are amorphous, have a Ge:Si composition of 55:45 and 185 nm thickness. The film structure was investigated by XRD and TEM, and the electrical behaviour was studied by measuring current–voltage (<italic>I</italic>–<italic>V</italic>) and current–temperature (<italic>I</italic>–<italic>T</italic>) characteristics and by discussing them in correlation with the structure. Different electrical behaviours of GeSi films corresponding to different structures have been evidenced. The 700 °C annealed GeSi films are formed of nanocrystals (7–15 nm) separated by amorphous regions (1–2 nm). These films present a superlinear <italic>I</italic>–<italic>V</italic> characteristic typical of high field‐assisted tunnelling through potential barriers (amorphous regions) between nanocrystals. The <italic>I</italic>–<italic>T</italic> characteristic at low temperature follows a <italic>T</italic><sup>−1/2</sup> law showing a thermally activated tunnelling of carriers between neighboring GeSi nanocrystals. The films annealed at 800 and 900 °C have a like behavior, they are completely crystallized and present linear <italic>I</italic>–<italic>V</italic> and Arrhenius <italic>I</italic>–<italic>T</italic> dependences reflecting the polycrystalline behaviour. <inline-graphic xlink:href="ark:/27927/pghqqrqqtk" content-type="pssb201350112-gra-0001" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /></p> </sec> </abstract>