Recently ozone is one of natural hazards which comes from cars, industry using ozone for sterilization of organic and inorganic materials and for water purification. So, ozone sensing becomes very important, and convenient and accurate ozone sensor is required. A new high sensitivity ozone sensing system using an deep ultra-violet light emitting diode (DUV-LED) operated at the wavelength of 280 nm has been successfully constructed. The fabrication of diode operated at 280 nm is much easier than that of DUV-LED operated at Hg lamp wavelength of 254 nm. The system is compact and possible to sense the ozone concentration less than 0.1 ppm with an accuracy of 0.5% easily with low power DUV-LED of around 200 micro Watts operated at 280 nm without any data processing circuit.
The importance of ozone sensing has recently increased, because ozone is harmful gas which is generated from industrial use of ozone for sterilization and cleaning of biomaterials and semiconductor devises and also water sterilization. Furthermore, ozone is produced in the surface air by photochemical reactions involving unburned fuel vapors and nitrogen oxides produced at high temperatures by car engines. So, the depletion of ozone is very important. So, continuous, high-sensitivity easy detection of ozone is indispensable.
Ozone sensing is currently conducted by monitoring the conductance change in thin-film-like semiconductors containing ZnO [1,2], In2O3 [3,4]. Previous studies have tried to measure ozone using a galvanic technique [
We recently developed a new type of ozone sensing system using a low-power deep ultra violet light emitting diode (hereafter DUV-LED) operated at the wavelength of 280 nm as a light source, instead of an Hg lamp. This system has the advantages of being very compact, having a long lifetime, and being free from any harmful materials.
In this report, we present our experimental results and demonstrate the utility of this system.