Preparation, Characterization and Gas Sensing Performance of Pure SnO2 Thin Films Deposited using Physical Vapour Deposition Technique

Abstract

Nanocrystalline SnO 2 thin films were successfully prepared using Physical Vapour Deposition technique and were annealed at 400 o C. Structural, morphological, elemental, compositional, optical, and IntroductionSince last few decades there has been an increasing interest to prepare inexpensive SnO 2 thin films. Tin oxide is the most widely used metal oxide semiconductor in gas sensing because of its capability to detect combustible and hazardous gases such as methane, LPG, CNG, CO, CO 2 , Cl 2 , H 2 S etc [1][2][3][4]. It is an n-type semiconductor of tetragonal structure with band gap energy about 3.6 eV at room temperature. It is cheap, nontoxic and has strong oxidizing power, high photochemical corrosive resistance, good electrical, optical and piezoelectric behavior. In recent years, semiconductor metal oxide films have received considerable attention because of their potential applications [5] such as photochemical and photoconductive devices in LCD, lithium-ion batteries,[6-8] a transport conductive electrode for solar cells [9,10] a gas sensing material for gas sensor devices [11], transport conducting electrodes [12] etc. The majority of the applications adopted SnO 2 as the sensing material due to its high sensitivity and stability at lower operational temperatures, in spite of its poor selectivity [13].Out of many thin film preparation techniques such as chemical vapour deposition [14], spray pyrolysis [15], sputtering [16], activated reactive evaporation [17], etc. Physical Vapour Deposition method is straight forward and simple one. Because of deposition in high vacuum and at room temperature, this technique produces contamination free uniform thin films. In the present study, we used Hind Hivac vacuum depositing unit for depositing pure tin onto the cleaned glass substrates at room temperature. The films were then heated in muffle furnace at 200 o C for 24 hrs to allow oxidation. The so formed pure SnO 2 thin films were then annealed at 300, 400 and 500 o C each for 2 hrs. Structural, morphological, electrical, optical and gas sensing characterizations of the samples were studied.

A simple low cost method for synthesis of SnO2 nanoparticles and its characterization

“…SnO 2 can be synthesized by various methods like crystal spray pyrolysis, hydrothermal methods, thermal evaporation, microwave-assisted combustion method, sol-gel method and electrochemical synthesis as mentioned in previous literatures [5][6][7][8][9][10][11][12][13] [7]. Thakre et al made SnO 2 thin solid films through physical vapour deposition technique.…”

Gas Sensing Studies of Tin Oxide Thin Films Annealed at Different Temperatures

“…Structural, surface morphological and electrical studies were carried out; results were interpreted and systematically tabulated in our previous papers [12,13]. To avoid repetition, details of only gas sensing studies are given over here.…”

Modified Sn-doped LaCrO3 nanostructures: focus on their characterization and applications as ethanol sensor at a lower temperature

“…In the field of gas sensing, the most commonly used metal oxide semiconductor is tin oxide. The reason behind it is the potential to recognize ignitable and polluted gases such as methane, LPG, CNG, CO, CO 2 , Cl 2 , H 2 S, and so on [22,23].…”