Optical Properties of Sol-Gel Nb₂O₅ Films with Tunable Porosity for Sensing Applications

Table 1

Refractive index (), extinction coefficient (), thickness (), volume fractions of air () and acetone () in %, absolute reflectance change , and refractive index change after exposure to acetone vapors as a function of Pluronic PE6100/NbCl₅ ratio.

Sample name	PE6100/NbCl5	(600 nm)	(600 nm)	(nm)	(%)	(%)		(%)
S1	0 : 1	2.198	2.6 ⋅ 10^−2	44	0	0	0	0
S2	0.07 : 1	1.615	2.4 ⋅ 10^−2	99	46	0.6	0.014	4.3
S3	0.14 : 1	1.668	2 ⋅ 10^−2	94	41	0.5	0.011	4.2
S4	0.23 : 1	1.507	1.8 ⋅ 10^−2	125	54	1.1	0.028	5.3
S5	0.46 : 1	1.513	1.8 ⋅ 10^−2	124	54	0.88	0.023	5.3