Efficient Flexible Counter Electrode Based on Modified Graphite Paper and in Situ Grown Copper Sulfide for Quantum Dot Sensitized Solar Cells

Abstract

Flexible counter electrode (CE) plays an important role in portable quantum dot sensitized solar cells (QDSCs). However, the present power conversion efficiency (PCE) of bendable QDSC is rather limited partly due to the unsatisfactory conductivity, flexibility, catalytic activity, and fabrication technique of CE. In this work, flexible CEs composed of Cu x S and graphite paper (GP) are built and fabricated through a facile successive ionic layer adsorption reaction (SILAR) method. Through designing and optimizing of the surface property of GP, coverage, and thickness of catalyst, excellently performed CEs are achieved with the maximal PCE of 8.70% under one full sun illumination for Zn–Cu–In–Se QDSCs. Further, fully flexible QDSCs assembled with the as-prepared CEs and plastic photoanodes show a high PCE of 2.45% under the same illumination.

Flexible CdS/CdSe quantum dots sensitized solar cells with high performance and durability

“…The preparation of flexible Cu 2 S counter electrode adopts successive ionic layer adsorption and reaction method. [ 10 ] First ITO‐PEN substrate was immersed in anhydrous ethanol and deionized water in ultrasonic cleaning respectively. After dried at room temperature, it was immersed in a mixed solution of 20 mL hydrogen peroxide (30%) and 20 mL ammonia (25%) for 30 minutes at 50℃, and air dried at room temperature.…”

Fabrication of Quantum Dot-Sensitized Solar Cells Based on a Transparent TiO2 Film with Reasonable Load Resistance Design

“…18 For the sol−gel method, the nanoparticles are likely to cluster together after the subsequent high-temperature calcination treatment. 19 When using the microemulsion method to prepare transparent TiO 2 films, the chemical reaction activity of nanoparticles is reduced by the surfactant, and the transparency is not ideal. 20,21 The general way is to reduce photoanode thickness for enhanced transparency, which inversely induces the declined power conversion efficiency (PCE).…”

“…Because of the extensive application of TiO 2 nanomaterials, the preparation techniques of TiO 2 are widely researched. , At present, the preparation methods of the TiO 2 nanomaterials can mainly be sorted as the gas phase method, solid phase method, and liquid phase method. , The deposition rate of the transparent TiO 2 film by the gas phase method is low, with a low volume of production and high cost. , The energy consumption of the solid phase method is high, while the purity is low, and the morphology is difficult to control. , The liquid phase method is the most common method for preparing TiO 2 nanomaterials, mainly including electrodeposition, sol–gel, microemulsion, precipitation, water (solvent) heat, etc . For the sol–gel method, the nanoparticles are likely to cluster together after the subsequent high-temperature calcination treatment . When using the microemulsion method to prepare transparent TiO 2 films, the chemical reaction activity of nanoparticles is reduced by the surfactant, and the transparency is not ideal. , The general way is to reduce photoanode thickness for enhanced transparency, which inversely induces the declined power conversion efficiency (PCE) .…”

Black TiO2-Based Dual Photoanodes Boost the Efficiency of Quantum Dot-Sensitized Solar Cells to 11.7%

“…Although numerous wide bandgap semiconductors such as ZnO, SnO 2 , and ZnS have been used as photoanodes in QDSSCs, TiO 2 is still the most extensively used material due to its excellent chemical stability, non-toxicity, and low cost, etc. [ 6 , 7 , 8 ]. Limited by the wide bandgap, TiO 2 can only absorb ultraviolet light, which accounts for ~5% of sunlight.…”