The Study of Absorbing Layers for Pyroelectric Detectors
碩士 === 國立中山大學 === 電機工程學系 === 87 === The porous metal-black absorbing layers were deposited by the thermal evaporation with metal materials of silver (Ag) and gold (Au) as evaporation source in various gas atmospheres (Ar and N2). The process parameters and characteristics of The porous me...
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Format: | Others |
Language: | zh-TW |
Published: |
1999
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Online Access: | http://ndltd.ncl.edu.tw/handle/55397710173486839061 |
Summary: | 碩士 === 國立中山大學 === 電機工程學系 === 87 === The porous metal-black absorbing layers were deposited by the thermal evaporation with metal materials of silver (Ag) and gold (Au) as evaporation source in various gas atmospheres (Ar and N2). The process parameters and characteristics of The porous metal-black absorbing layers were deposited by the thermal evaporation with metal materials of silver (Ag) and gold (Au) as evaporation source in various gas atmospheres (Ar and N2). The process parameters and characteristics of The porous metal-black absorbing layers were studied in this thesis. The optimal absorbing layer was applied to the pyroelectric thin film infrared (IR) detectors. The effects of the porous absorbing layer on voltage responsivity (Rv) and specific detectivity (D*) of pyroelectric IR detectors were discussed.
Experimental results reveal that various deposition pressure and gas atmosphere will influence strongly on surface morphology development and absorption characteristic of Ag and Au-black thin film. With an increase of deposition pressure, the amount of porosity and IR absorption increase. The change of crystallization and σ×d of porous thin film can be seen obviously. The optimal process parameters of the absorbing layer are Ag-black thin films deposited in an Ar gas atmosphere at a pressure of 750 mTorr. The IR absorption of Ag-black thin film is 96% at 3 μm of wavelength of incident light.
For the application of IR detectors, Ag-black thin film was deposited on the calcium modified lead titanate [(Pb1-xCax)TiO3,PCT(x=0.25)] pyroelectric thin film. We found that the voltage responsivity (Rv) increased from 4533 V/W without absorbing layer up to 5543 V/W with absorbing layer at 20 Hz. The specific detectivity (D*) increased from 3.27×107 cmHz1/2/W without absorbing layer up to 3.78×107 cmHz1/2/W with absorbing layer at 100 Hz. The results show that Rv and D* of the IR detector with absorbing layer are 1.22 and 1.16 times as large as those of the IR detector without absorbing layer, respectively.
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