Photo-EMF sensitivity of porous silicon thin layer-crystalline silicon heterojunction to ammonia adsorption.
A new method of using photo-electromotive force in detecting gas and controlling sensitivity is proposed. Photo-electromotive force on the heterojunction between porous silicon thin layer and crystalline silicon wafer depends on the concentration of ammonia in the measurement chamber. A porous silicon thin layer was formed by electrochemical etching on p-type silicon wafer. A gas and light transparent electrical contact was manufactured to this porous layer. Photo-EMF sensitivity corresponding to ammonia concentration in the range from 10 ppm to 1,000 ppm can be maximized by controlling the intensity of illumination light.
Electrical and Computer Engineering Division, Hanyang Institute of Technology, Hanyang University, 17 Haengdang-dong, Sung-dong-gu, 133-791 Seoul, Korea. vashpanov@hanyang.ac.kr
Yuriy
Y
Vashpanov
Jae Il
JI
Jung
Kae Dal
KD
Kwack
D000327:Adsorption / Q000528:radiation effects; D000641:Ammonia / Q000032:analysis*; D003460:Crystallization; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods*; D008027:Light; D053770:Nanowires / Q000737:chemistry; D009584:Nitrogen / Q000032:analysis; D016062:Porosity / Q000528:radiation effects; D012825:Silicon / Q000737:chemistry*; D013816:Thermodynamics
D000641:Ammonia; D009584:Nitrogen; D012825:Silicon