Electrochemistry of Inorganic OCT-PbS/HDA and OCT-PbS Photosensitizers Thermalized from Bis(N-diisopropyl-N-octyldithiocarbamato) Pb(II) Molecular Precursors

Abstract

Inorganic nanocrystal solar cells have been tagged as the next generation of synthesizers that have the potential to break new ground in photovoltaic cells. This synthetic route offers a safe, easy and cost-effective method of achieving the desired material. The present work investigates the synthesis of inorganic PbS sensitizers through a molecular precursor route and their impact on improving the conversion efficiency in photovoltaic cells. PbS photosensitizers were deposited on TiO 2 by direct deposition, and their structure, morphologies and electrocatalytic properties were examined. The X-ray diffraction (XRD) confirms PbS nanocrystal structure and the atomic force microscopy (AFM) displays the crystalline phase of uniform size and distribution of PbS, indicating compact surface nanoparticles. The electrocatalytic activity by lead sulfide, using N-di-isopropyl-N-octyldithiocarbamato (OCT) without hexadecylamine (HDA) capping (OCT-PbS) was very low in HI-30 electrolyte, due to its overpotential, while lead sulfide with OCT and HDA-capped (OCT-PbS/HDA) sensitizer exhibited significant electrocatalytic activity with moderate current peaks due to a considerable amount of reversibility. The OCT-PbS sensitizer exhibited a strong resistance interaction with the electrolyte, indicating very poor catalytic activity compared to the OCT-PbS/HDA sensitizer. The values of the open-circuit voltage (V OC ) were~0.52 V, with a fill factor of 0.33 for OCT-PbS/HDA. The better conversion efficiency displayed by OCT-PbS/HDA is due to its nanoporous nature which improves the device performance and stability. resistance of charge transport at the counter electrode/electrolyte interface (R1). At low frequencies, 132 the impedance related to the charge transport at the TiO2/PbS/electrolyte interface is R2. This study 133 focused only on the R2 to compare the effect of the HDA capping agent on the charge transfer and 131 resistance of charge transport at the counter electrode/electrolyte interface (R1). At low frequencies, 132 the impedance related to the charge transport at the TiO2/PbS/electrolyte interface is R2. This study 133 focused only on the R2 to compare the effect of the HDA capping agent on the charge transfer and 134 transport at the TiO2/PbS/electrolyte interfaces. The impedance at low frequencies can be pinpointed 135 using R2. When the R2 is lower, the charge transfer is faster at the photosensitzer/electrolyte interface. 136OCT-PbS/HDA indicated a very poor catalytic activity, which can be linked to the injection of HDA. 137On the other hand, the OCT-PbS sensitizer displayed lower charge transfer at the 138 photosensitzer/electrolyte interface. This can be linked to the particle size of OCT-PbS sensitizer, 139 which promotes the charge transport speed of the solar cell. This further affirmed the CV and AFM 140 result [40,41]. However, R2 is also considered as a resistance of charge recombination at the interfaces 141 of TiO2/QDs/electrolytes. Decreases in R2 can boost the charge recombination and shorten electron 14...

Inorganic Pb(II)–P and Pb(II)–S Complexes as Photosensitizers from Primary and Secondary Amines in Dyes-Sensitized Solar Cells

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Colloidal Synthesis and Characterization of Molybdenum Chalcogenide Quantum Dots Using a Two-Source Precursor Pathway for Photovoltaic Applications

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Proficient One-Step Heat-Up Synthesis of Manganese Sulfide Quantum Dots for Solar Cell Applications

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