Multi-Channel Exploration of O Adatom on TiO2(110) Surface by Scanning Probe Microscopy.

Huan Fei Wen,Yasuhiro Sugawara,Yan Jun Li

doi:10.3390/nano10081506

Huan Fei Wen, Yasuhiro Sugawara + Show 1 more

Open Access

https://doi.org/10.3390/nano10081506

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Abstract

We studied the O2 dissociated state under the different O2 exposed temperatures with atomic resolution by scanning probe microscopy (SPM) and imaged the O adatom by simultaneous atomic force microscopy (AFM)/scanning tunneling microscopy (STM). The effect of AFM operation mode on O adatom contrast was investigated, and the interaction of O adatom and the subsurface defect was observed by AFM/STM. Multi-channel exploration was performed to investigate the charge transfer between the adsorbed O and the TiO2(110) by obtaining the frequency shift, tunneling current and local contact potential difference at an atomic scale. The tunneling current image showed the difference of the tunneling possibility on the single O adatom and paired O adatoms, and the local contact potential difference distribution of the O-TiO2(110) surface institutively revealed the charge transfer from TiO2(110) surface to O adatom. The experimental results are expected to be helpful in investigating surface/interface properties by SPM.

Highlights

Scanning probe microscopy (SPM) has developed as a powerful tool for exploring the surface properties and surface dynamic process at an atomic scale on a semiconductor or insulator [1–10]
Atomic manipulation has been realized, and surface chemical reactions have been observed with atomic resolution by atomic force microscopy (AFM)
Local density of states (LDOS) gives significant information of the electronic structure of the surface, which is measured by scanning tunneling microscopy (STM)

Summary

Introduction

Scanning probe microscopy (SPM) has developed as a powerful tool for exploring the surface properties and surface dynamic process at an atomic scale on a semiconductor or insulator [1–10]. Based on AFM, Kelvin probe force microscopy (KPFM) was developed to characterize the contact potential difference (CPD) between the substrate and cantilever tip. Different modes of KPFM have been successfully used to simultaneously measure surface structures and LCPD, and the surface potential of TiO2(110) was measured [13–19].

Results

Conclusion