Premium
Influence of Ga dopant on photoelectrochemical characteristic of Ga‐doped ZnO thin films deposited by sol–gel spin‐coating technique
Author(s) -
Huang MaoChia,
Lin JingChie,
Cheng ShuoHan,
Weng WeiHeng
Publication year - 2017
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.6176
Subject(s) - spin coating , photocurrent , materials science , dopant , doping , analytical chemistry (journal) , thin film , scanning electron microscope , raman spectroscopy , annealing (glass) , crystallite , band gap , electrical resistivity and conductivity , sol gel , optics , optoelectronics , nanotechnology , composite material , chemistry , metallurgy , physics , electrical engineering , engineering , chromatography
In this study, Ga‐doped ZnO thin films were prepared using sol–gel technique via spin‐coating method. The effect of Ga‐doping dopant (0, 1, 2 and 3 at.%) on microstructural, optical, electrical and photoelectrochemical (PEC) characteristics have been investigated. The spin‐coating was repeated six times, and as‐obtained thin films were then annealed at 500 °C for 1 h in vacuum. After annealing, all samples revealed single phase of hexagonal ZnO polycrystalline structure with a main peak of (002) in X‐ray diffraction (XRD) pattern. Raman spectra show that the vibration strength of E 2 is highly decreased by Ga doping. Thicknesses of all samples were ~300 nm measured via scanning electron microscopy (SEM) cross‐section images and alpha‐step. The optical band gap and resistivity of samples were in the range of 3.24 to 3.28 eV and 102 to 9 Ohm cm, respectively. Resulting from PEC response, the 2 at.% Ga‐doped ZnO thin film has a better PEC performance with photocurrent density of ~0.14 mA/cm 2 at 0.5 V versus saturated calomel electrode (SCE) under illumination with the intensity of 100 mW/cm 2 . This value was about seven times higher than the un‐doped film (reference sample). Observed higher photocurrent density was likely because of a suitable Ga‐doping concentration causing a lower resistivity. Copyright © 2016 John Wiley & Sons, Ltd.