Increasing the efficiency of graphene-based Schottky-barrier devices

Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 11617, Taiwan

Adv. Mater. Lett., 2019, 10 (2), pp 132-135

DOI: 10.5185/amlett.2019.2183

Publication Date (Web): Dec 19, 2018

Copyright © IAAM-VBRI Press

E-mail: yphsieh@gate.sinica.edu.tw

Abstract

Graphene’s high carrier mobility and ambipolar nature has the potential to improve electronic devices. The absence of a band-gap necessitates heterostructure devices. Schottky-barrier devices consisting of an interface between graphene and a semiconductor represent the simplest heterostructure. Despite its simplicity, graphene-based Schottky barrier devices are not well understood and exhibit low injection efficiencies. We here investigate the impact of graphene/metal interaction on the properties of the Schottky-barrier. Besides the commonly employed Au/graphene we use Pt/graphene contacts. We find that the injection efficiency for Pt is 5x higher than for Au and systematically study the origin of this behavior. We identify a large difference in Richardson’s constant due to changes in the density of surface states. The demonstrated ability to increase the injection current was applied to improve the efficiency of graphene-based Schottky solar cells by 13x. 

Keywords

Graphene, schottky barrier, richardson, solar cell.