Density Functional Study of the Cluster Model of SnO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;(110) Surface Modified by Benzoic Acids

Tegshjargal Khishigjargal,Kazuyoshi Ueda,Chimed Ganzorig,Masaru Sakomura,Namsrai Javkhlantugs,Youji Kurihara

doi:10.4236/wjnse.2013.33007

Abstract

The properties of the modified surface of SnO2(110) with benzoic acid (Y-C6H4-COOH: Y is para position relative to -COOH group) derivatives were investigated using density functional theory. Zehner et al. mentioned that the modification of surface dipole moment made it possible to tune the work function of the system. The experiment of Ganzorig et al. showed that there was a linear relationship between the dipole moment of the binding molecule and the work function change of the system using the modified surface of indium-tin oxide (ITO) with some benzoic acid derivatives. To elucidate the relation between the dipole moment of the molecule and the work function change, we investigated the modified surface of SnO2(110) using Sn7O14 cluster model which was embedded in the fixed point charges. On the modification of the surface, benzoic acid derivatives were bound to SnO2 surface. By changing the terminal group of benzoic acid with H, Cl, F, CF3 and CCl3, the work function changed and the dipole moment of the binding molecules of the modified SnO2(110) were evaluated. The results showed that there was a linear relationship between the dipole moment of the binding molecules and the work function changed. From this relation, the average value of the dipole moments of Sn-OOC linkage at the surface was also evaluated.

Highlights

The tuning of the work function of metal oxide is important in the research on the application field of the electronic devices [1]
The experiment of Ganzorig et al showed that there was a linear relationship between the dipole moment of the binding molecule and the work function change of the system using the modified surface of indium-tin oxide (ITO) with some benzoic acid derivatives
To elucidate the relation between the dipole moment of the molecule and the work function change, we investigated the modified surface of SnO2(110) using Sn7O14 cluster model which was embedded in the fixed point charges

Summary

Introduction

The tuning of the work function of metal oxide is important in the research on the application field of the electronic devices [1]. The modification of the surface with self assembled monolayer (SAM) has been known as a method to change the work function of the metal oxide substrates [2,3]. One of such metal oxide substrates is tin oxide (SnO2), which has been used for gas sensors, transparent conductors, and catalysts [4]. Many researchers studied molecular adsorption and oxygen vacancies of tin dioxide surface theoretically [16,17] to interpret how tin dioxide surfaces sense gases [18] and conduct electric current [19]. We studied the work function change of the SnO2(110) surface using the density functional theory (DFT) with the cluster model of

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Results