Adsorption and Cation-Exchange Behavior of Zinc Sulfide on Mesoporous TiO₂ Film and Its Applications to Solar Cells

Abstract

Zinc sulfide (ZnS) was deposited onto the surface of mesoporous TiO2 film by a typical successive ionic layer adsorption and reaction (SILAR) process. By inducing a spontaneous cation exchange between ZnS and a target cation (Pb2+, Cu2+, Ag+, or Bi3+) dissolved in a chemical bath when they are in contact, it was demonstrated successfully that white translucent ZnS on the substrate could be changed to new brown-colored metal chalcogenides and the amount of ZnS deposited originally by different conditions could be compared in a qualitative way with the degree of color change. By utilizing this simple but effective process, the evolution of a well-known ZnS passivation layer prepared from different chemical baths in quantum dot (QD)-sensitized solar cells could be tracked visually by checking the degree of color change of TiO2/ZnS electrodes after the induced specific cation exchange. When applied to representative CdS QD-sensitized solar cells, it was revealed clearly how the different degrees and rates of ZnS deposition could affect the overall power conversion efficiency while finding an optimized passivation layer over TiO2/CdS electrode. An acetate anion-coupled Zn2+ source was observed to give a much faster deposition of a ZnS passivation layer than a nitrate anion one because of its higher pH-induced more-favorable adsorption of Zn2+ on the surface of TiO2. As another useful application of the ZnS-based cation exchange, as-deposited ZnS was used as a template for preparing a more complex metal chalcogenide onto a mesoporous TiO2 film. The ZnS-derived Sb2S3-sensitized electrode showed a promising initial result of over 1.0% overall power conversion efficiency with a very thin ZrO2 passivation layer between TiO2 and Sb2S3.

Electrodeposited Ni-Rich Ni–Pt Mesoporous Nanowires for Selective and Efficient Formic Acid-Assisted Hydrogenation of Levulinic Acid to γ-Valerolactone

“…The use of porous materials as catalysts is an attractive solution for minimizing the volume of high-cost materials, and particularly, mesoporous materials offer high surface-to-volume ratios and provide more reaction sites than their traditional bulk counterparts. 28 − 33 Electrodeposition is one of the most promising technologies for the preparation of mesoporous catalysts due to the low preparation time, low cost, and the straightforward experimental setup. 34 − 36 Electrochemistry is a versatile tool for synthesizing mesoporous micro- and nanoarchitectured catalysts via templated electrodeposition using hard and/or soft templates, if not both simultaneously, or via electrochemical dealloying.…”

“…The use of porous materials as catalysts is an attractive solution for minimizing the volume of high-cost materials, and particularly, mesoporous materials offer high surface-to-volume ratios and provide more reaction sites than their traditional bulk counterparts. − Electrodeposition is one of the most promising technologies for the preparation of mesoporous catalysts due to the low preparation time, low cost, and the straightforward experimental setup. − Electrochemistry is a versatile tool for synthesizing mesoporous micro- and nanoarchitectured catalysts via templated electrodeposition using hard and/or soft templates, if not both simultaneously, or via electrochemical dealloying. − During the last two decades, the relatively high level of control of pore-size distribution and pore definition added to the low cost, high-scalability potential, and ease of operation of soft-templated electrodeposition have been immensely significant drivers of electrodeposition for mesoporous fabrication. ,− Among the different soft-template systems, block copolymer-templated electrodeposition offers greater robustness and uniform controllable mesoporosity. , Additionally, the use of electrochemical methods such as electrodeposition allows their simultaneous use as both soft and hard templates, which affords control of both the shape and porosity of the prepared material. ,− Notably, the combination of hard- and soft-template-assisted electrodeposition provides a huge specific surface in the prepared Ni–Pt structures. The block copolymer and applied potential are responsible for the mesoporous character and the Ni/Pt ratio, respectively.…”

A Comprehensive Review on Third-Generation Photovoltaic Technologies

“…For DSSCs to meet consumer expectations and increase their commercialization, their [68] intrinsic and extrinsic stability must be equivalent to Si-solar cells. Two examples of the sealing components used in DSSCs to enclose the cells are Surlyn and Bynel hotmelt foils.…”

“…Two examples of the sealing components used in DSSCs to enclose the cells are Surlyn and Bynel hotmelt foils. Internal pressure buildup and exposure to cyclic or regular temperature variations reduce their sealability [68]. Although they are inexpensive and simple, their use cannot be disregarded.…”