Comparison of the effects of different ionic liquid-gels on the efficiencies of the PbSe, PbS and PbTe quantum dot sensitized solar cells

Abstract The semiconductor nanocrystal quantum dots (QD) are used in the third generation solar cells due to their high photon conversion efficiency. In this study, we investigated the effects of ionic liquid on the efficiency of lead chalcogenide (PbSe, PbTe and PbS) QD solar cells. To achieve this, we looked at the interaction between the alkyl groups (R = CH3) and the thiol bonds (SH) of the selected organic electrolytes. Two different classes of liquids were prepared based on organic (960 and SB) and inorganic (AY1-3) ionic liquid (IL) where AY1-3 liquid include LiI, NaI, I2 materials; 960 and SB type liquids include BMII, tBP and GuNCS materials. These liquids provide redox reactions. 5 different ILs were applied to each of the 3 types of QDs and 15 solar cells were produced. Particle sizes and solar cell parameters like fill factor and efficiencies were determined through optical absorption, photoluminescence, TEM, SEM, EDS and J-V measurements. It was observed that the interaction of these groups affected the fill factor (FF), open circuit voltage (Voc) and efficiency of PbX (X = Se, S, Te) QD solar cells. The AY1 was found to be compatible with the PbX QDSSCs when used alone while the AY2 was not. LiI was an effective IL when used alone which resulted in with an efficiency of 7.853 for PbS QDSSC. NaI and GuSCN introduced different pairs of redox to the system, increasing the efficiency of PbSe solar cells to 8.257.