Chitosan/P3HT biohybrid films as polymer matrices for the in‐situ synthesis of CdSe quantum dots. Experimental and theoretical studies

Biohybrid nanocomposite films were obtained through a simple two‐step methodology. Films of chitosan/poly(3‐hexylthiophene) (CS/P3HT) were used as polymer matrices for the in‐situ synthesis and stabilization of CdSe quantum dots. The biohybrid materials were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR‐FTIR), Raman spectroscopy, UV–visible spectroscopy, thermogravimetric analysis (TGA), field emission scanning electron microscope (FESEM), high‐resolution transmission electron microscopy (HRTEM), and photoluminescence spectroscopy (PL). The effects of the P3HT composition on the properties of the QDs in the films were analyzed. The results confirmed that CS/P3HT films provided an adequately confining matrix for the growth of CdSe QDs with a fairly uniform size and revealed that the interactions between the CdSe nanoparticles and the CS/P3HT matrix mainly involved the OH and NH2 groups. The optical band gaps of the biohybrid nanocomposite films were estimated. The results of photoluminescence revealed that a charge transfer phenomenon occurred in the polymer system. Finally, theoretical analyses suggest that the CdSe QDs would be preferentially located onto the chitosan domains. In‐situ formation of CdSe quantum dots, QDs, into chitosan/P3HT biohybrid films, through a simple two‐step methodology was achieved. The presence of P3HT diminishes the optical band gap value of the CS/P3HT/CdSe biohybrid films. The interaction between P3HT and CdSe QDs originate electronic transfer phenomena. Theoretical analyses suggest noncovalent interactions between QDs and the matrix.