▎ 摘　　要

Porphyrin sensitized solar cells (PSSC) has been successfully fabricated composed of graphene quantum dots (GQD) functionalized ZnO photoanodes, zinc tetrakis (4-carboxy phenyl)porphyrin (TCPPZn) as sensitizer and polypyrrole coated oxidised multiwalled carbon nanotubes (PPy/OMWCNT) as counter electrode. The effect of the concentration of GQD on the structural, morphological, photophysical and photovoltaic properties of GQD@ZnO, and GQD@ZnO/TCPPZn nanocomposites has also been investigated. Studies indicate that TCPPZn adsorbed on the surface on GQD@ZnO. Hot electron injection mechanism and multiple exciton generation from GQD to ZnO were mainly responsible for the photoexcitation response in PSSC. This study indicates that GQD can play role of sensitizer to some extent. The time decay measurements reveals the evidences of FRET mechanism, and synergistic interaction between GQD and TCPPZn. The J(sc), V-oc, PCE of the corresponding PSSC devices enhanced initially and then decreased. Among all the devices fabricated, the PSSC with a 40% amount of GQD (GQD@ZnO/TCPPZn 40%) attains the best performance with the J(sc) = 10.1 mA/cm(2), V-oc = 0.48, PCE = 2.45% FF = 0.507 higher than ZnO@TCPPZn device fabricated without GQD. Overall, this design provides a new concept for the development of photoanodes which derive better efficiency for dye sensitized solar cell (DSSC) and PSSC at economical low cost.