Table 6.

Summary of response of light-activated sensors operated at room temperature. (The response is defined as the ratio between R_a and R_g: R_a/R_g if there is no special definition in the table. ΔR, ΔG, ΔI is the absolute value of change of resistance, conductance and current respectively).

Material	Light Illumination	Temperature	Vapor	Concentration (ppm)	Response	Ref
ZnO	UV 3.6 mW/cm2 (365 nm)	RT	Ethanol	100	0.14	[64]
SnO2-GaN nanowires	UV 3.75 mW/m2 (365 nm)	RT	Ethanol	500	1.01	[105]
ZnO nanodisk	UV 1.6 mW/cm2 (365 nm)	RT	Ethanol	100	1.17	[106]
ZnO thin film	UV	RT	H2	100	0.1 ΔR/Rair	[36]
ZnO nanoline	UV	RT	H2	100	0.2	[36]
ZnO	White light LED	RT	Ethylene	5200	1.06	[37]
ZnO	White light LED	RT	H2O2	100	0.5 ΔR/Rg	[42]
SnO2	UV	RT	CO	200	0.84 ΔG/Gair	[16]
TiO2 NWs-80 nm	UV	RT	NH3	100	0.5 ΔZ/Zair	[60]
TiO2 NWs-550 nm	UV	RT	NH3	100	0.1	[60]
ZnO	UV	RT	Ethanol	60	0.8 ΔI/Iair	[14]
ZnO	Visible light	RT	HCHO	110	1.35% ΔI/Iair	[10]
Cu/ZnO	355 nm	RT	ethanol	1120	64% ΔI/Iair	[11]
Cu/ZnO	355 nm	RT	acetone	1120	63% ΔI/Iair	[11]