High-Efficiency CdS Quantum-Dots-Sensitized Solar Cells with Compressed NanocrystallineTiO2Photoelectrodes

Yanan Wang,Hongling Li,Ning Peng,Xuduo Bai

doi:10.1155/2012/858693

Abstract

Nanocrystalline TiO2films were fabricated on titanium substrates by compression method. The CdS quantum dots (QDs) were assembled onto the compressed TiO2layers, which serve as sensitizers. A maximum power conversion efficiency of 4.49% is achieved under 100 mW/cm2illumination. In this paper, we find that the compression can help increase the efficiency of the cell by increasing the absorption of the CdS QDs and improving the transportation of photogenerated electrons.

Highlights

Dye-sensitized solar cells (DSSCs) have established themselves as an alternative to conventional solar cells owing to their remarkably high power conversion efficiency, longtime stability, and low-cost production [1, 2]
The twostep dipping procedure is termed as one S-CBD cycle and the incorporated amount of CdS can be increased by repeating the assembly cycles
The performances of the photoelectrochemical (PEC) solar cells were studied in a three-armed cell with a platinum filament counter electrode and a saturated calomel electrode (SCE) as a reference. 0.1 M Na2S solution serves as the electrolyte

Summary

Introduction

Dye-sensitized solar cells (DSSCs) have established themselves as an alternative to conventional solar cells owing to their remarkably high power conversion efficiency, longtime stability, and low-cost production [1, 2]. QDs-sensitized solar cells usually use a sintered TiO2 film as the photoelectrode In such a device, a lot of energy and time is consumed in the fabrication of TiO2 films; the power conversion efficiency (η) is mainly limited by the small amount of the QDs on the electrode surface and the electron recombination in the cell [2, 4]. The TiO2 film was fabricated using the compression method developed by Anders Hagfeldt and coworkers [9–11] This method can offer a simple and fast way to fabricate TiO2 films; it was proved that the resulting films are porous and mechanically stable [9, 11]. We expect that this method would help resolve the problems mentioned above

Experiment

Results and Discussion

Cell 4 Cell 5 Cell 6