Detection of oxidising gases using an optochemical sensor system based on GaN/InGaN nanowires

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• 作者：Konrad Maier^aAuthor Vitae ; Andreas Helwig^a ; ^{andreas.helwig@eads.net" class="auth_mail}Author Vitae ; Gerhard Mü ; ller^aAuthor Vitae ; Pascal Becker^bAuthor Vitae ; Pascal Hille^bAuthor Vitae ; Jö ; rg Schö ; rmann^bAuthor Vitae ; Jö ; rg Teubert^bAuthor Vitae ; Martin Eickhoff^bAuthor Vitae
• 关键词：III-Nitride semiconductors ; Nanowires ; Photoluminescence ; Gas sensor ; Oxidizing gases ; Optochemical
• 刊名：Sensors and Actuators B: Chemical
• 出版年：5 July, 2014
• 年：2014
• 卷：197
• 期：Complete
• 页码：87-94
• 全文大小：1392 K

文摘

We report on an all-optical sensor system that employs GaN/InGaN nanowire heterostructures (NWH) as optochemical transducers. When exposed to ultraviolet light, such NWHs emit green luminesce light. This photoluminescence (PL) is intense and temperature stable, and persists up to transducer temperatures well beyond 200 掳C. When exposed to oxidizing gases such as O₃, NO₂, and O₂ the PL intensity decreases. At room temperature minimum detectable O₃-, NO₂-, and O₂-concentrations are 50 ppb, 500 ppb and 100 ppm, respectively. Above their minimum detectable concentrations the O₃, NO₂ and O₂ responses increase in a quasi-logarithmic manner up to a temperature-dependent saturation level. It is shown that the observed features can be explained within a model of Langmuir adsorption and surface recombination.