Narrow band defect luminescence from Al-doped ZnO probed by scanning tunneling cathodoluminescence

Edward M Likovich,Rafael Jaramillo,Kasey J Russell,Shriram Ramanathan,Venkatesh Narayanamurti

doi:10.1063/1.3647622

Abstract

We present an investigation of optically active near-surface defects in sputtered Al-doped ZnO films using scanning tunneling microscope cathodoluminescence (STM-CL). STM-CL maps suggest that the optically active sites are distributed randomly across the surface and do not correlate with the granular topography. In stark contrast to photoluminescence results, STM-CL spectra show a series of sharp, discrete emissions that characterize the dominant optically active defect, which we propose is an oxygen vacancy. Our results highlight the ability of STM-CL to spectrally fingerprint individual defects and contribute to understanding the optical properties of near-surface defects in an important transparent conductor.

Highlights

Likovich, Edward M., Rafael Jaramillo, Kasey J
We present an investigation of optically active near-surface defects in sputtered Al-doped ZnO films using scanning tunneling microscope cathodoluminescence (STM-CL)
In stark contrast to photoluminescence results, STM-CL spectra show a series of sharp, discrete emissions that characterize the dominant optically active defect, which we propose is an oxygen vacancy

Summary

Introduction

We present an investigation of optically active near-surface defects in sputtered Al-doped ZnO films using scanning tunneling microscope cathodoluminescence (STM-CL). In stark contrast to photoluminescence results, STM-CL spectra show a series of sharp, discrete emissions that characterize the dominant optically active defect, which we propose is an oxygen vacancy.

Results

Conclusion