In₂O₃- and SnO₂-Based Thin Film Ozone Sensors: Fundamentals

Table 3

The best parameters of conductometric heated ozone sensors designed on the base of metal oxides.

	Technological route,; parameters of sensing layer	Max. sensor; response	Conditions of measurements	Response time	Recovery times	References
In2O3	Thick film: d~100 nm, t~12 nm	~3 · 10^2	85°C, 250 ppb, dry	25–45 s	n/a	[35]
	Thick film: d—n/a, t~8 nm	~1.5 · 10^3	300°C, 100 ppb, dry	~1 min	~10 min	[50, 51]
	Thick film: d—n/a, t~8 nm	~(4–6) · 10^3	350°C, 76 ppb	n/a	n/a	[33]
	Thick film: d~20 μm, t~20 nm	120	270°C, 1 ppm, dry	n/a	n/a	[52]
	Thin films: d~30–50 nm, t~10–15 nm	10^3–10^4	200–300°C, 1 ppm	<2 s (280°C)	~20 s (280°C)	[43, 44, 53, 54]
	Thin films: d—n/a, t—n/a	~10^2	400°C, 60 ppb	100 min (250°C)	60–80 min (250°C)	[46]
	Thin films: d—n/a, t—n/a	~3 · 10^2	370°C, 230 ppb	n/a	n/a	[55]
SnO2	Thick film: d~100 nm, t~15 nm	~(3-4) · 10^2	120°C, 250 ppb, dry	40–60 s	Tens of minutes	[35]
	Thin films: d~30–50 nm, t~10–15 nm	10^3–10^4	200–300°C, 1 ppm	<2 s (280°C)	~15 min (280°C)	[45, 56, 57]
	Thin films: d~260 nm, t—n/a	~10^2	350°C, 135 ppb	Several minutes	Several minutes	[58, 59]
	Thin films: d~300 nm, t—n/a	~10	350°C, 60 ppb	n/a	n/a	[60, 61]
	Thin films: d~20–30 nm, t~6–8 nm	~10^3	320°C, 1 ppm	<2-3 s	~15 min	[47]
	Thin films: d~40–50 nm,  nm	~10^5	150°C, 1 ppm	3-4 s (200°C)	~17 min (200°C)	[62]
WO3	Thick film: d—n/a, t~15 nm	~600	180°C, 1 ppm	~15 s	~2 min	[35]
	Thick film: d—n/a, t—n/a	~35	400°C, 80 ppb	n/a	n/a	[63]
	Thin films: d~100 nm, t—n/a	~6 · 10^2–7 · 10^3	120°C, 90 ppb	~12 s	1–3 min	[64]
	Thin films: d~35–50 nm, t~20–100 nm	5–300	250°C, 0.8 ppm	0.5–2 min	2-3 min	[65–69]
	Thin films: d~300 nm, t—n/a	~20	300°C, 200 ppb	Minutes	Minutes	[63]
	Thin films: d—n/a, t~20 nm	1.5 · 10^3	300°C, 500 ppb	n/a	n/a	[70]
ZnO	Thick film: d—n/a, t~160 nm	~8	250°C, 0.1 ppm	14 s	9 s	[71]
	Thick film: d~275 nm, —n/a	~10–30	200°C, 300 ppb	~10 s	~2 min	[72]
MoO3-TiO2	Thick film: d—n/a, —n/a	1.7	370°C, 100 ppb	~20 s	n/a	[73]
Fe2O3	Thin films: ~500 nm, —n/a	~20	200°C, 0.5 ppm, 50%	n/a	n/a	[74]
SmFeO3	Thick film: d—n/a, —n/a	~10^2	285°C, 0.4 ppm	~1 min	~10 min	[75]

d: film thickness; t: grain size; sensor response (/); conditions of measurements: temperature of operation, gas concentration, and humidity.