Numeral Description of Grain Size Effects of Tin Oxide Gas-Sensitive Elements and Evaluation of Depletion Layer Width

作者：Liu, Jianqiao^*; Jin, Guohua; Zhai, Zhaoxia; Monica, Faheema Fairuj; Liu, Xuesong

来源：Electronic Materials Letters, 2015, 11(3): 457-465.

DOI：10.1007/s13391-015-4399-0

• tin oxide
• gas sensor
• grain size effect
• depletion layer width

The grain size effects on tin oxide gas-sensitive elements are numerically described by the model of gradient-distributed oxygen vacancies, which extends the receptor function of semiconductors to the condition of inhomogeneous donor density in grains. The sensor resistance and the response to the reducing gas are formulated as functions of the grain size and the depletion layer width. The simulations show good agreement with the experimental results. The depletion layer width is estimated as 4 nm for the undoped SnO2 element, whereas the values are 2 and 7 nm for Sb-doped and Al-doped samples, respectively. The results are experimentally verified by the donor-doped SnO2 thin films, the depletion layer widths of which are evaluated on the basis of the correlation between the electrical resistance and the Sb-doping amount. The location of the Fermi level is found to be a crucial factor that dominates the evaluation results.

• 出版日期2015-5
• 单位大连海事大学