Schottky Junction Methane Sensors Using Electrochemically Grown Nanocrystalline-Nanoporous ZnO Thin Films

Table 2

Response, response time, and recovery time of different noble metal contacts on ZnO thin film (calculated from Figure 6).

% of CH4	Response			Response time (s)			Recovery time (s)
	Pt	Pd-Ag	Rh	Pt	Pd-Ag	Rh	Pt	Pd-Ag	Rh
0.01	0.18	0.99	1.22	52.2	22.3	130.2	58	48.3	148.3
0.05	0.29	1.38	1.82	40.2	19.7	52.2	42.3	46.2	120
0.1	0.62	2.21	2.48	27.9	16.4	42.8	30.1	38.1	89.2
0.5	0.68	3.11	3.87	20.3	12.1	38.2	26.2	20.2	80.2
1	0.71	3.81	4.39	18.8	8.8	30.2	22.8	16	78.4