Table 1.

shows the fluorescence lifetime data of Ag nanocluster at different excitation when observed at peak emission wavelength

Excitation Wavelength (nm)	Observation Wavelength (nm)	τ1 (ns)	τ2 (ns)	τ3 (ns)	Amplitude Weighted Average Lifetime (ns) < τ >	Intensity Weighted Average Lifetime (ns) $\stackrel{‒}{\tau }$	X2
480	605	0.05	0.5	1.5	0.4	1.0	1.14
525	635		0.4	1.5	0.6	1.0	1.51
575	665		0.5	1.7	0.8	1.2	1.29
600	690		0.6	1.8	1.1	1.4	1.16
630	725	0.2	1	2.3	1.0	1.6	1.05
668	760	0.2	1	2.4	1.1	1.6	1.03
725	800	0.2	1	2.3	1.0	1.6	1.04

τ₁, τ₂ and τ₃ are different components of fluorescence lifetime in nanoseconds.

$<\tau >=\underset{i}{\Sigma }{\alpha }_i{\tau }_i$

$\stackrel{‒}{\tau }=\underset{i}{\Sigma }{f}_i{\tau }_i$, Where, $f_i=\frac{{\alpha }_i{\tau }_i}{\underset{i}{\Sigma }{\alpha }_i{\tau }_i}$

X²= Goodness of fit