V 770 double beam spectrophotometer

The molecular structures of the pure and dyed chitosan films were investigated using Bruker ALPHA FTIR spectrophotometer in a spectral range (400–4000) cm⁻¹. Furthermore, optical transmission and reflection spectra of the fabricated thin films in the UV-visible-NIR were assessed using a Jasco V-770 double-beam spectrophotometer in a range of (190–2500) nm. The influence of the dyeing of pure chitosan thin films on its emission spectrum was inspected using a Shimadzu RF-5301 PC spectrofluorophotometer under a 350 nm excitation source. The shielding characteristics of the designed films for visible light were tested under a green laser diode (532 nm). The colorimetric parameters of the engineered films were identified using UltraScan Pro. (HunterLab, Reston, VA, USA). All color measurements were taken under the conditions of the standard illuminant D65 and 10° observers, as described by the Commission Internationale de L’éclairage (CIE L* a* b* standard).
Eventually, the light sensitivity of the designed metal/polymer/semiconductor (MPS) architectural junctions employing silver as a rectifier metal electrode, virgin and dyed chitosan as a polymeric film, and p-type silicon as a semiconductor was evaluated under halogen light of irradiance 100 mW/cm² under forward and reverse bias of driving voltage in the range ±3 volts using Keithley 6516B electrometer.

All chemicals were purchased from Sigma-Aldrich, Acros Organics, Merck, VWR or TCI and used without further purification if not stated otherwise. UV–vis absorbance measurements were performed with a V-770 double beam spectrophotometer (JASCO) at 25 °C. Samples for spectroscopic measurements were prepared in disposable 1 mL semi-micro PMMA cuvettes (BRAND). Transmission electron microscopy was performed using a Titan Themis G3 300 TEM (FEI) operating at 300 kV or a Libra 200 FE electron microscope (Zeiss) operating at 200 kV. The ζ-potential measurements were carried out on a Nano ZS Zetasizer (Malvern Instruments) at 25 °C and samples were prepared in disposable DTS 1060 capillary cells (Malvern Instruments). The syntheses of the tCD and tTEG can be found in Supporting Information File 1.