Fast highly-sensitive room-temperature semiconductor gas sensor based on the nanoscale Pt-TiO2-Pt sandwich

被引：64

作者：

Plecenik, T. ^{[1
]}

Mosko, M. ^{[1
,2
]}

Haidry, A. A. ^{[1
]}

Durina, P. ^{[1
]}

Truchly, M. ^{[1
]}

Grancic, B. ^{[1
]}

Gregor, M. ^{[1
]}

Roch, T. ^{[1
]}

Satrapinskyy, L. ^{[1
]}

Moskova, A. ^{[2
]}

Mikula, M. ^{[1
]}

Kus, P. ^{[1
]}

Plecenik, A. ^{[1
]}

机构：

[1] Comenius Univ, Fac Math Phys & Informat, Dept Expt Phys, Bratislava 84248, Slovakia

[2] Slovak Acad Sci, Inst Elect Engn, Bratislava 84104, Slovakia

来源：

SENSORS AND ACTUATORS B-CHEMICAL | 2015年 / 207卷

关键词：

Hydrogen; Gas sensor; Nanoscale; Sandwich; Room temperature; TiO2; HYDROGEN; OXIDES; SIZE;

D O I：

10.1016/j.snb.2014.10.003

中图分类号：

O65 [分析化学];

学科分类号：

070302 ; 081704 ;

摘要：

Development of fast highly-sensitive semiconductor gas sensors operating at room temperature, which would be compatible with semiconductor technology, remains a challenge for researchers. Here we present such sensor based on a nanoscale Pt-TiO2-Pt sandwich. The sensor consists of a thin (similar to 30 nm) nanocrystalline TiO2 layer with similar to 10 nm grains, placed between the bottom Pt electrode layer and top Pt electrode shaped as a long narrow (width w down to 80 nm) stripe. If we decrease w to similar to 100 nm and below, the sensor exposed to air with 1% H-2 exhibits the increase of response (R-air/R-H2) up to similar to 10(7) and decrease of the reaction time to only a few seconds even at room temperature. The sensitivity increase is due to a nontrivial non-ohmic effect, a sudden decrease (by three orders of magnitude) of the electrical resistance with decreasing w for w similar to 100 nm. This non-ohmic effect is explained as a consequence of two nano scale-related effects: the hydrogen- diffusion-controlled spatially-inhomogeneous resistivity of the TiO2 layer, combined with onset of the hot-electron-temperature instability when the tiny grains are subjected to high electric field. (C) 2014 The Authors. Published by Elsevier B.V.

引用

页码：351 / 361

页数：11

共 24 条

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