Influence of a bifunctional linker on the loading of Cu2AgInS4QDs onto porous TiO2NFs to use as an efficient photoanode to boost the photoconversion efficiency of QDSCs

In the present study, quaternary Cu(2)AgInS(4)quantum dots (CAIS QDs) are synthesized by a hot injection method. The crystallographic information of the QDs is confirmed by X-ray diffraction and high-resolution transmission electron microscopy studies. Energy dispersive X-ray spectrum analysis reveals a 1.93 : 1.0 : 1.01 : 3.80 elemental composition ratio of the synthesized QDs. X-ray photoelectron spectroscopy analysis confirms the oxidation states of the elements present in the synthesized QDs. The optical properties are studied using UV-VIS absorption spectroscopy and PL emission spectroscopy. From a Tauc plot, the bandgap of the synthesized QDs is calculated to be 1.6 eV. The synthesized QDs are used as sensitizers and are loaded onto P-TiO(2)NFs using 3-mercaptopropionic acid as a bifunctional linker as well as without the use of a bifunctional linker. Quantum dot sensitized solar cells (QDSCs) are fabricated using Cu(2)AgInS(4)QD sensitized porous TiO(2)NFs as the photoanode, Cu2S as the counter electrode and polysulphide as the electrolyte, in order to study its photovoltaic performance. These results revealed that the QDs loaded onto the porous TiO(2)NFs using a bifunctional linker exhibits 27% improvement in the photoconversion efficiency of QDSC than that of the QDs loaded onto the porous TiO(2)NFs without the use of a bifunctional linker.