For the spectrum of GO, the broad band ranging from 3600 to 3000 cm-1 corresponds to the O-H stretching vibrations of adsorbed water molecules [45].
It can be seen that in all cases, the emission is characterized for a broad band ranging from 3.38 eV (365 nm) to 2.52 eV (490 nm) for the smaller irradiation time while, for the larger irradiation time, the full-width at half-maxima is widened and extends to 2.24 eV (550 nm).
The strong broad band ranging from 3200 to 3600 cm−1 usually corresponds to the possibility of overlapping between the –NH and the –OH stretching vibrations, and the strong sharp band at the wavenumber region of 3400 3550 cm−1 is characteristic of the –OH stretching vibration [ 24].
As a result, the closed-ring isomer facilitated intramolecular π-electron delocalization and exhibited a broad absorption band ranging from 200 to 850 nm.
Transmission and reflection parameters are acquired within a broad frequency band, ranging from 23 to 30 GHz, and used for the evaluation of the power loss in the waveguide and to extract the C/C electrical conductivity.
The broad PL band ranging from 300 to 550 nm of all the samples could be the result of defects, including oxygen vacancies in the crystal with electronic energy levels below the 4f band [38].
The broad absorption band ranges from 3,000 to 3,340 cm−1, which is attributed to the protonation of amine functional group at polymer backbone and is observed for the highly doped PANI Emeraldine salt.
The PL spectrum shows a weak emission at 430 nm and a broad strong emission band ranging from 520 to 700 nm.
In the FTIR of dye loaded CR (Fig. 3d), the broad and intense band ranging from 3,831 to 3,189 cm−1 can be ascribed to the hydrogen bonded –OH vibrations of the cellulosic structure of CR.
