Electrical and Electronic Engineering 2015, 5(1A): 19-22
DOI: 10.5923/c.eee.201501.04
ZnO Nanostructure Decorated Microgap Electordes
UV Sensor
Q. Humayun
1,*
, U. Hashim
2
, C. M. Ruzaidi
1
, Kai Loong Foo
2
1
Department of Electronics Faculty of Engineering Technology, Universiti Malaysia Perlis (UniMAP), D/A Pejabat Pos Besar Kangar,
Perlis, Malaysia
2
Nano Biochip Research Group, Institute of Nano Electronic Engineering (INEE), Universiti Malaysia Perlis (UniMAP), Kangar, Perlis,
Malaysia
Abstract The larger surface-area-to-volume ratio compared with their bulk counterpart, Nanomaterials based electronic
devices are the subject of keen interest, probably because of cost effective nature and fast sensing capabilities. Moreover
the control morphology at specific area of electrodes is a challenging task. Therefore in the current research article the ZnO
thin film and ZnO nanorods were selectively deposited by low cost sol-gel and hydrothermal growth process at the
selective area of microgap electrodes spacing and further electrically tested for ultraviolet (UV) sensing application. On
exposure to ultraviolet (UV) light the current gains, response/recovery times, repeatability, of the fabricated sensors
displayed the promising application for UV light detection. The surface morphologies structural, optical and electrical
properties of the as synthesized nanostructures ZnO were characterized using SEM, XRD, and source meter respectively.
Keywords Micro-gap, Sol gel, Hydrothermal, ZnO thin film, ZnO Nanorods, Ultraviolet light (UV)
1. Introduction
During the last few decades, nanomaterials have been the
subject of extensive interest because of their potential use in
a wide range of fields like, optoelectronics, catalysis and
sensing applications [1-3]. Due to smaller size and larger
surface area to volume ratio, nanomaterials comprised novel
physical and chemical properties that are difficult to observe
in conventional and bulk counterparts [4]. Generally there
are three types of nanomaterials (one-dimensional (1D),
two-dimensional (2D) and three-dimensional (3D)) have
been fabricated [5]. Presently, nanomaterials based research
areas are rapidly expanding and growing [6]. Moreover
metal oxide based nanomaterials have drawn a special
attention because of attractive properties coupled with
efficient flexibility in structures [7].
Physically ZnO „‟Zinc Oxide‟‟ is existed in white powder
form. Naturally ZnO exhibit n-type conductivity, while its
p-type conductivity can be generated by special synthesis
process [8]. Generally n-type conductivity might because of
intrinsic defects and oxygen vacancies [9].
ZnO can be synthesized by variety of different techniques
with different morphologies, such as pulsed laser deposition
(PLD) [10], sputtering [11], chemical vapor deposition
sol-gel [12] and metal organic chemical vapor deposition
* Corresponding author:
qhumayun2@gmail.com (Q. Humayun)
Published online at http://journal.sapub.org/eee
Copyright © 2015 Scientific & Academic Publishing. All Rights Reserved
(MOCVD) [13] etc.
The solution based methods is low cost, simple, need low
temperature and also scalable for large areas. ZnO is
considering good candidate for electronic device application.
Properties of direct and wide band gap allow ZnO to function
at high break down voltages, low noise, high temperature
and power [14]. Such characteristics could enhance the
application of ZnO for light emitting application mainly blue
and ultraviolet light emission diodes [15]. High exciton
binding energy (60 meV) of ZnO shows the light emission
efficiency at room temperatures [16]. Moreover for solar cell
technology transparency properties of ZnO allow to use as
transparent electrodes [17].
Ultraviolet (UV) photodetector has an important role in
various commercial and military applications, such as secure
space-to-space communications, pollution monitoring, water
sterilization, early missile plume detection, fire alarm,
environmental monitoring, and high temperature flame
detection [18]. Therefore it is necessary to fabricate high
performance low-cost UV sensors to control the effect of UV
radiation [16]. The measurement of UV radiation is different
from visible radiation, because direct optical instrument
could not detect UV radiation properly [19].
2. Experimental
2.1. Mask Design
To align the nanostructures at desired area of electrodes
spacing and, to achieve good resolution during pattern