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

Abstract

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.

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

“…According to Akman’s [ 40 ] research, doping the Mn/ZnO photoanode in solar cell applications resulted in stability and an improvement in efficiency of 2.11–4.20% for 3.34-3.19 eV. Fadaam et al [ 41 ] demonstrated enhanced conversion for MnS through annealing at 300 °C with a band-gap energy of 2.9 eV. Cao et al [ 42 ] reported on the heterojunction structure of NiS2/MnS with 6.44 % and 4.81% for MnS FTO as a potential counter electrode to replace Pt as a low-cost and highly efficient material for dye-sensitized solar cells.…”

Simple strategies deployed for developing efficient and stable solution processed quantum dot solar cells

“…However, several other concepts upgrading the PA/QDs passivation methods reported will be discussed in detail. 110–113…”

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

“…MoS2 exhibited the lowest PCE; this was due to the nanoparticles having a higher charge transfer resistance, which resulted in Power conversion efficiency for the developed solar cells increased in the following order: MoS 2 (6.05%) < MoTe 2 (6.93%) < MoSe 2 (7.05%). MoS 2 exhibited the lowest PCE; this was due to the nanoparticles having a higher charge transfer resistance, which resulted in the limitation of electron transfer, subsequently resulting in low electron-hole recombination, hence, in limited efficiency [22]. Low efficiency might be due to the increased surface area and thickness on the photoanode which results in charge transfer resistance [23,24].…”