Influence of bifunctional linker on loading of Cu2AgInS4 QDs onto porous TiO2 NFs to use as an effective photoanode to boost up the photoconversion efficiency of QDSC
In the present study, a quaternary Cu2AgInS4 quantum dots 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. The energy dispersive X- ray spectrum analysis reveals 1.93: 1.0:1.01:3.80 elemental composition ratio of the synthesized QDs. X-ray photo electron spectroscopy analysis confirms the oxidation states of the elements present in the synthesized QDs. The optical properties are studied by using UV-Vis absorption spectrum and PL emission spectrum. From the Tauc plot, the bandgap of the synthesized QDs is calculated to be 1.6eV. The synthesized QDs are used as the sensitizers and loaded onto the P- TiO2 NFs using 3-mercaptopropionic acid as a bifunctional linker and without using a bifunctional linker. Quantum dot sensitized solar cells (QDSCs) are fabricated using 2AgInS4 QDs sensitized porous TiO2 NFs as the photoanode, Cu2S as the counter electrode and polysulphide as the electrolyte to study its photovoltaic performance. These results revealed that the QDs loaded onto the porous TiO2 NFs using a bifunctional linker have exhibited a 52% improvement in the photoconversion efficiency than that of loaded onto the porous TiO2 NFs without using a bifunctional linker.