Open AccessPreparation and gas-sensing properties of the silver nanoparticles/porous silicon composite
Author(s) -
Deyue Yan,
Shenyu Li,
Shiyu Liu,
Yimei Zhu
Publication year - 2015
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.64.137102
Subject(s) - materials science , porous silicon , silicon , wafer , nanoparticle , scanning electron microscope , microstructure , silver nanoparticle , deposition (geology) , composite number , etching (microfabrication) , monocrystalline silicon , nanocrystalline silicon , nanotechnology , chemical engineering , layer (electronics) , composite material , crystalline silicon , optoelectronics , engineering , paleontology , sediment , amorphous silicon , biology
The p-type porous silicon layer with the aperture about 1.5 microns and hole depth about 15-20 microns is prepared by electrochemical etching of a p-type monocrystalline silicon wafer with a resistivity 10-15 Ω·cm and along [100] orientation in a double-tank cell which consists of the electrolyte (volume ratio HF: DMF=1:2). Silver nanoparticles film with different thickness has been deposited on porous silicon by the electroless deposition for different deposition times. Morphology and microstructure of the silver nanoparticles/porous silicon composite are studied by scanning electron microscope and X ray diffracmeter. Result indicates that the silver nanoparticles are uniformly distributed on the surface of porous silicon and the deposition time has an important influence on the morphology of the composite. The gas-sensing properties of the silver nanoparticles/porous silicon composite to NH3 are tested at room temperature by the static volumetric method. Results show that the deposition time has a significant impact on the gas-sensing properties of the silver nanoparticles/porous silicon. In a short deposition time, the composite with an appropriate amount of silver nanoparticles doped on the porous silicon shows good gas-sensing properties to NH3 with high sensitivity, fast response-recovery characteristic due to the high specific surface area and special microstructure. At room temperature, the gas sensor has a sensitivity of about 5.8 to 50 ppm NH3.