solvent-free hydrothermal synthesis of network-like graphene quantum dots (gqd) nano particle and ultrasonic tio2/gqd nanocomposite

The enhancement of solar cell efficiency, is required to use materials of a good electrical properties. in this work, the graphene quantum dots (gqd) created from starch as precursor has been performed in single pot using a hydrothermal process. the tio2/gqd nano-composite was prepared using an in-depth ultrasonic technique to use as a semiconductor in a solar cell. the investigated using techniques such as: ft-ir, fe-sem, xrd, raman spectrum. additionally, the synthesis and the characterization of novel porphyrin derivatives with amide, were designed as sensitizers in dye-synthesized solar cells (dsscs). five derivatives were synthesized via a one-pot reaction of porphyrin with amines, and their optimal yield was obtained under various conditions. the synthesized dyes were characterized using techniques such as melting point analysis, mass spectroscopy, ft-ir, 1h,13c-nmr and esi-mass. the obtained results demonstrated that the 6b dye exhibited with the high efficiency of 1.86 % at am 1.5, followed by 6a with 1.82 %, 8a with 1.34 %, and 8b with 1.14 %, as compared to the control cell (n719) with an efficiency of 5.4 %.