Design of CdSeXS1-X/ZnS quantum dot sensitized solar cell

Abstract

Quantum Dot Sensitized Solar Cells (QDSSCs) are a high potential element of third generation solar energy systems, which has recently been viewed as an alternative to first- and second-generation solar cells. In this study, CdSexS1-x QDSSCs were designed and their performances were examined depending on parameter changes. TiO2 surfaces are coated on Fluorine doped tin oxide glass (FTO) surface in 3 layers by doctor blade method. CdSexS1-x QDs were coated on TiO2 surface by Successive Ionic Layer Adsorption and Reaction (SILAR) method, and it was aimed to improve surface passivation and electron transfer with ZnS coated with SILAR method. In the study, the selenium and sulphur amount in CdSexS1-x QDs were tested at different rates, and SILAR cycles of QD and ZnS were tested between 1-5 cycles. It was determined that the highest Power Conversation Efficiency (PCE) value was obtained with CdSe0.8S0.2 QDSSC where the amount of Se was 4 times the amount of S, CdSexS1-x QDs were coated as 5 SILAR cycles and ZnS was coated as 3 SILAR cycles. The PCE of CdSe0.8S0.2 QDSSCs was found to be 1.87%. In this case, it has been clearly demonstrated that modulation of Se to CdS QDs, which is one of the most used QDs in the literature, increases the performance of the QDSSC. In addition, the effects of the SILAR cycle, in which the amount of QD coated on the surface is controlled, and therefore the thicknesses of the QDs on the QDSSC performance have been discussed