Improved Performance of CdS/CdTe Quantum Dot-Sensitized Solar Cells Incorporating Single-Walled Carbon Nanotubes

Abstract

We fabricated quantum dot-sensitized solar cells (QDSSCs) using cadmium sulfide (CdS) and cadmium telluride (CdTe) quantum dots (QDs) as sensitizers. A spin coated TiO 2 nanoparticle (NP) film on tin-doped indium oxide glass and sputtered Au on fluorine-doped tin oxide glass were used as photo-anode and counter electrode, respectively. CdS QDs were deposited onto the mesoporous TiO 2 layer by a successive ionic layer adsorption and reaction method. Pre-synthesized CdTe QDs were deposited onto a layer of CdS QDs using a direct adsorption technique. CdS/CdTe QDSSCs had high light harvesting ability compared with CdS or CdTe QDSSCs. QDSSCs incorporating single-walled carbon nanotubes (SWNTs), sprayed onto the substrate before deposition of the next layer or mixed with TiO 2 NPs, mostly exhibited enhanced photo cell efficiency compared with the pristine cell. In particular, a maximum rate increase of 24% was obtained with the solar cell containing a TiO 2 layer mixed with SWNTs.

I-V Characteristics of Cadmium Telluride Quantum Dots Diode Fabricated by Drop Casting Method

“…Semiconductor nanocrystals known as Quantum Dots (QDs) have attracted remarkable consideration in the fabrication of devices such as optoelectronic, photovoltaic and photoluminescent devices [1] due to their size dependent physical and chemical properties [2]. II-VI semiconductors possess such properties which are suitable for device fabrications [3].…”