Effect of the functionalization of CdS nanoparticles in the in-situ synthesis of P3HT/CdS composites

Abstract In this work, in-situ oxidative synthesis and properties of composites based in poly(3-hexylthiophene) (P3HT) with functionalized cadmium sulfide (CdS) nanoparticles (P3HT/CdS) are reported. CdS nanoparticles were synthesized by chemical precipitation and they were functionalized with diethyl[2-hydroxy-2-(thiophen-3-yl)ethyl] phosphonate. P3HT-CdS composites were synthesized by in-situ oxidative polymerization of 3-hexylthiophene (3HT) monomers in the presence of un-functionalized (as reference) and functionalized CdS nanoparticles (3HT/CdS weight ratio of 1:0.21). P3HT/CdS composites were characterized by 1 H NMR, FTIR, XRD, TGA, UV–Vis, and AFM analysis. Effect of functionalization of CdS on properties in P3HT/CdS composites was studied. A higher interaction between P3HT and CdS was obtained with functionalized CdS. Functionalization of CdS in P3HT-CdS composites led to increased optical absorbance, crystallinity, decomposition temperature and stability. In addition, their evaluation in photovoltaic devices is reported. Higher energy conversion efficiency of glass/ITO/PEDOT:PSS/P3HT-CdS: PC 71 BM/PFN/FM devices was achieved when the CdS was functionalized.