Improved photovoltaic performances of Ru (II) complex sensitized DSSCs by co-sensitization of carbazole based chromophores

Exploring optical, electrochemical, thermal, and theoretical aspects of simple carbazole-derived organic dyes

This study highlights the recent advancements in organic electronic materials and their potential for cost-effective optoelectronic devices. The investigation focuses on the molecular design, synthesis, and comprehensive analysis of two organic dyes, aiming to explore their suitability for optoelectronic applications. The dyes are strategically constructed with carbazole as the foundational structure, connecting two electron-withdrawing groups: barbituric acid (Cz-BA) and thiobarbituric acid (Cz-TBA). These dyes, featuring carbazole as the core and electron-withdrawing groups, demonstrate promising spectral, optical, electrochemical, thermal, and theoretical properties. They show strong potential for diverse optoelectronic applications, promising efficient light absorption and robust stability. The results endorse their suitability for practical optoelectronic systems.

Improvement of Power Conversion Efficiency of Quantum Dot-Sensitized Solar Cells by Doping of Manganese into a ZnS Passivation Layer and Cosensitization of Zinc-Porphyrin on a Modified Graphene Oxide/Nitrogen-Doped TiO2 Photoanode

It is vital to acquire power conversion efficiencies comparable to other emerging solar cell technologies by making quantum dot-sensitized solar cells (QDSSCs) competitive. In this study, the effect of graphene oxide (GO), nitrogen, manganese, and a porphyrin compound on the performance of QDSSCs based on a TiO₂/CdS/ZnS photoanode was investigated. First, adding GO and nitrogen into TiO₂ has a conspicuous impact on the cell efficacy. Both these materials reduce the recombination rate and expand the specific surface area of TiO₂ as well as dye loading, reinforcing cell efficiency value. The maximum power conversion efficiency of QDSSC with a GO N-doped photoelectrode was 2.52%. Second, by employing Mn²⁺ (5 and 10 wt %) doping of ZnS, we have succeeded in considerably improving cell performance (from 2.52 to 3.47%). The reason for this could be for the improvement of the passivation layer of ZnS by Mn²⁺ ions, bringing about to a smaller recombination of photoinjected electrons with either oxidized dye molecules or electrolyte at the surface of titanium dioxide. However, doping of 15 wt % Mn²⁺ had an opposite effect and somewhat declined the cell performance. Finally, a Zn-porphyrin dye was added to the CdS/ZnS by a cosensitization method, widening the light absorption range to the NIR (near-infrared region) (>700 nm), leading to the higher short-circuit current density (J _SC) and cell efficacy. Utilizing an environmentally safe porphyrin compound into the structure of QDSSC has dramatically enhanced the cell efficacy to 4.62%, which is 40% higher than that of the result obtained from the TiO₂/CdS/ZnS photoelectrode without porphyrin coating.

Enhancing photovoltaic performance of DSSCs sensitized with Ru-II complexes by D–π–A configured carbazole based co-sensitizers

Simple D–π–A architectured carbazole based dyes, P1–4, were employed as co-sensitizers in DSSCs sensitized with Ru-II complexes, viz.NCSU-10 and N3. The results revealed that, the NCSU-10 sensitized devices displayed improved photovoltaic performance when co-sensitized with P1 and P3.