ABSTRACT
In this study, lead(II) sulphide (PbS) nanoparticles of varying particle sizes were synthesized using the hot injection method, employing 1-octadecene (ODE) as a coordinating ligand in conjunction with oleylamine (OAm). This synthesis approach was compared with the preparation of hexagonal-shaped nanoparticles through the ligand of 1-Dodecanethiol (DT), resulting in DT-capped PbS nanoparticles. The prepared nanoparticles were characterized using multiple techniques including photoluminescence (PL), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). The condensation reaction of DT ligands led to various nanoparticles within the range of 34.87 nm to 35.87 nm across different synthesis temperatures (120 °C, 150 °C, 180 °C, 210 °C, and 240 °C). The PbS with DT ligands exhibited a highly crystalline and superhydrophilic structure. Interestingly, near-infrared (NIR)-PL analysis revealed peaks at 1100 nm, representing the lowest-energy excitonic absorption peak of PbS nanoparticles for both ligands. This suggests their potential utility in various applications, including IR photoreactors, as well as in the development of non-toxic nanoparticles for potential applications in in vivo bioimaging.
ABSTRACT
Perovskite CsPbI3 quantum dots (QDs) were synthesized as a hole-transporting layer (HTL) of a planar perovskite solar cell (PSC). By using the Octam solution during the ligand engineering, CsPbI3 QDs exhibits a denser grain and a larger grain size due to the short-chain ligands of Octam. In addition, CsPbI3 QDs with the Octam solution showed a smooth and uniform surface on MAPbI3 film, indicating the QDs improved the microstructure of the MAPbI3 perovskite film. As a result, the PSC with CsPbI3 QDs as an HTL has the optimal open-circuit voltage as 1.09 V, the short-circuit current as 20.5 mA/cm2, and the fill factor (FF) as 75.7%, and the power conversion efficiency (PCE) as 17.0%. Hence, it is inferred that introducing QDs as a HTL via the ligand engineering can effectively improve the device performance of the PSC.
