Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Gas sensors

Synthesis and Study of Modified Nanostructure Porous Silicon Layers for Chemical Gas Sensing

A.D.Thamir; A. L. Abed; F. Q. Mohammed; A. S. Hasan

Engineering and Technology Journal, 2017, Volume 35, Issue 10, Pages 970-974

In this work, We prepared a modified nanostructure porous silicon (PS) layers for effective chemical gas sensing. Nanopore covered microporous silicon gas sensor has been fabricated using electrochemical etching in an HF acid and ethanol solution. A porous silicon (PS) surface has been modified using selective depositions formed from metal to enhance the response to Sensing of CO2. (PS) has been interest for gas sensing because of the exceptional gathering of importent features. By setting the process parameters,the porosity, pore size, and the morphology can be modifid and practically controlled. The modified porous silicon layers were characterized using different techniques such as scanning electron microscopy(SEM)and a series of electrical characterizations to study the structures in the contact of the carbon dioxide was achieved.

Characterization of CuO:NiO/PS Hydrogen Gas Sensor

Isam M. Ibrahim; Yahya R. Hathal; Fuad T. Ibrahim; Mudhafar H. Ali

Engineering and Technology Journal, 2015, Volume 33, Issue 6, Pages 1066-1074

Thin films of copper oxide nanoparticles mixed with 6% nickel oxide are deposited on glass and Si substrates with orientation (111) utilizing pulsed laser deposition technique for the manufacture of hydrogen gas sensor. The films are annealed in air at 400 °C for two hours, then the structural and morphological properties are characterized using x-ray diffraction and atomic force microscopy. The results of CuO:NiO/Si films are exhibited a polycrystalline monoclinic CuO and cubic NiO phases. In addition, the peak of Si located at 28.3º which refer to (111) direction. Furthermore, this peak becomes very broad with varying full width at half maximum for etching current density of 30 mA/cm2 at time of 30 min which confirms the formation of pores on the crystalline silicon surface. On the other hand, the average diameter of 84.31 nm and 34.98 nm for CuO:NiO on a glass substrate and PS, respectively, were obtained. A sponge-like structure is produced for PS which reveal that a part of pores transform to a larger structure. The peak sensitivity of 204.8% was observed at optimum operating temperature of 350°C.