Wide range variation of resonance wavelength of GaZnO plasmonic metamaterials grown by molecular beam epitaxy with slight modification of Zn effusion cell temperatures
Journal
Journal of Alloys and Compounds
Journal Volume
870
Date Issued
2021
Author(s)
Cheng, Yung-Chen
Wang, Hsiang-Chen
Lai, Ho-Chine
Shi, Shih-Chen
Chen, Chi-Chung
Yao, Yu-Feng
Abstract
The innovative growth condition of heavily Ga-doped ZnO (GaZnO) plasmonic metamaterials is reported in this article. GaZnO epilayers are deposited by molecular beam epitaxy (MBE) with small variation of Zn effusion cell temperatures. The variation of Zn effusion cells temperatures are 330, 335, and 340 °C corresponding to Ga doping concentration 6.8, 6.3, and 3.2 at%, respectively, which are obtained from the measurements of energy-dispersive X-ray spectroscopy (EDX). Temperatures of Ga effusion cell and sapphire substrate are fixed at 735 and 250 °C in the growth. Hall effect measurements exhibiting free electron concentration of all samples approach 1021 cm?3. The lowest strain/stress (0.08%/0.34 GPa), the largest crystalline size (47.5 nm), the highest Hall mobility (30.1 cm2/Vs), and the lowest material loss of GaZnO epilayers are observed in Ga doping concentration 6.3 at% sample. Statistical analysis of root mean square (RMS) surface roughness declines from 3.1 to 1.74 nm in the atomic force microscope (AFM) measurements when the doping is increased from 3.2 to 6.8 at%. Wide range variation of plasmonic resonance wavelength from 1333 to 1515 nm with the raise of Ga doping concentration is acquired through the analysis of spectroscopic ellipsometry measurements. Slight variations of Zn effusion cell temperatures in the range of 330–340 °C bring about efficient and drastic change of Ga doping concentration as well as wide range variation of plasmonic resonance wavelength (1333–1515 nm) for the applications in fiber-optic communication. ? 2021 Elsevier B.V.
Subjects
Effusion cell temperatures
Ga-doped zinc oxide
Molecular beam epitaxy
Plasmonic resonance wavelength
Atomic force microscopy
Cells
Cytology
Electrons
Energy dispersive spectroscopy
Molecular beams
Plasmonics
Resonance
Spectroscopic ellipsometry
Surface roughness
X ray photoelectron spectroscopy
Zinc oxide
Cell's temperatures
Doping concentration
Effusion cell temperature
Effusion cells
Ga doping
Ga-doped zinc oxides
Ga-doped ZnO
Molecular-beam epitaxy
Resonance wavelengths
II-VI semiconductors
SDGs
Type
journal article