Fabrication and Characterisation of TiO2 Thin Film Methanol Vapor Sensor

Abstract

In this study, titanium dioxide (TiO₂) thin film with a thickness of approximately 250 nm was deposited on silicon dioxide (SiO₂) substrate using the pulsed DC sputtering technique to investigate gas sensing performance of methanol vapor detection. The structural, morphological, and vibrational characteristics of the film was analysed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and micro-Raman spectroscopy, respectively. UV–Vis spectrophotometry was used to analyse the optical properties, including light absorption behaviour, and to determine the band gap of the sensing material. For sensor measurements under methanol vapor ambient, aluminium interdigitated electrodes (IDEs) ohmic contacts were fabricated on the surface of the TiO₂ film using DC sputtering. The sensor was subsequently exposed to various concentrations of methanol vapor (up to 1900 ppm) at three different operating temperatures: 150 °C, 200 °C, and 250 °C. The dynamic gas sensing performance, including response and recovery times, was systematically monitored under each condition. The highest response was recorded at 250 °C, where the sensor exhibited a Ra/Rg value of 6.3 upon exposure to 1900 ppm methanol, along with the shortest response and recovery times. In contrast, at lower operating temperatures (150 °C and 200 °C), the sensor response decreased, and both the response and recovery times were significantly prolonged

Keywords

• TiO2 Thin Film
• Sensor
• Chemical Vapor
• Methanol

TiO₂ İnce Film Metanol Buharı Sensörünün Üretimi ve Karakterizasyonu

Abstract

Bu çalışmada, yaklaşık 250 nm kalınlığındaki titanyum dioksit (TiO₂) ince film, metanol buharının algılanmasına yönelik gaz algılama performansını araştırmak amacıyla pulse DC saçtırma tekniği kullanılarak silisyum dioksit (SiO₂) alttaş üzerine kaplanmıştır. Filmin yapısal, morfolojik ve titreşimsel özellikleri sırasıyla X-ışını kırınımı (XRD), taramalı elektron mikroskobu (SEM) ve mikro-Raman spektroskopisi kullanılarak analiz edilmiştir. Optik özellikler, ışık soğurma davranışı dahil olmak üzere, UV–Vis spektrofotometresi ile incelenmiş ve algılayıcı malzemenin bant aralığı belirlenmiştir. Metanol buharı ortamında sensör ölçümleri gerçekleştirebilmek için, TiO₂ film yüzeyine DC saçtırma yöntemiyle ohmik temas sağlayan alüminyum iç içe geçmiş elektrotlar (IDE) üretilmiştir. Sensör daha sonra üç farklı çalışma sıcaklığında (150 °C, 200 °C ve 250 °C) 1900 ppm’e kadar çeşitli metanol buharı konsantrasyonlarına maruz bırakılmıştır. Her bir koşul altında, yanıt ve iyileşme süreleri dahil olmak üzere dinamik gaz algılama performansı sistematik olarak izlenmiştir. En yüksek tepki, sensörün 250 °C’de 1900 ppm metanol buharına maruz kalmasıyla 6.3 (Ra/Rg)’lük tepki miktarı ve en kısa yanıt ile iyileşme sürelerini gösterdiği durumunda elde edilmiştir. Buna karşılık, daha düşük çalışma sıcaklıklarında (150 °C ve 200 °C) sensör tepkisi azalmış, yanıt ve iyileşme süreleri ise belirgin şekilde uzamıştır.

Keywords

• TiO2 İnce Film
• Sensör
• Kimyasal Buhar
• Metanol

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