Pulsed laser deposition of ZnO thin films decorated with Au and Pd nanoparticles with
enhanced acetone sensing performance
M. Alexiadou, M. Kandyla, G. Mousdis, and M. Kompitsas
National Hellenic Research Foundation, Theoretical and Physical Chemistry Institute, 48
Vasileos Constantinou Avenue, 11635 Athens, Greece
E-mail
Acetone
is a flammable volatile organic compound, which is widely used as an industrial
solvent. However, it can affect the central nervous system as well as the liver and kidney.
Additionally, acetone is contained in the human breath and may act as a biomarker for
disease diagnostics, such as type-1 diabetes and lung cancer. Also, it may enable accurate
monitoring of blood glucose levels for non-invasive and efficient diabetic patient self-
management. Therefore, sensitive and reliable acetone sensors are essential for medical,
environmental, and safety applications.
In this work, we compare the performance of pure thin-film ZnO acetone sensors with
nanocomposite ZnO:Au sensors (ZnO thin films with a surface partially covered by gold
nanoparticles) and ZnO:Pd sensors (ZnO thin films with a surface partially covered by
palladium nanoparticles) for low operating temperatures. We fabricate all sensors by pulsed
laser deposition (PLD). PLD is a versatile technique with a high instantaneous deposition
rate, which allows for the formation of thin films and nanoparticles with controllable
thickness as well as optical and electrical properties. The sensors operate in the temperature
range 159 – 200
o
C. The nanocomposite ZnO:Au and ZnO:Pd sensors have a lower detection
limit than the pure ZnO sensor, especially for lower operating temperatures. The
nanocomposite sensors are also more sensitive than the pure ZnO sensor, showing a response
enhancement factor between 2–7 for similar operating temperatures and acetone
concentrations. The ZnO:Pd sensor performs better than the ZnO:Au sensor and the sensing
mechanism is discussed. A study on the ZnO film thickness and the amount of palladium on
the ZnO surface reveals the ZnO:Pd sensor sensitivity increases with the amount of palladium
on the surface, while it remains roughly unchanged with the ZnO thickness. The lowest
acetone concentration we are able to detect is 26 ppm for the operating temperature of 200
o
C.
PS1 5
-161-
