Size-dependent photocurrent switching in chemical bath deposited CdSe quantum dot films

Cadmium Selenide Quantum Dots for Solar Cell Applications: A Review

Quantum dot-sensitized solar cells (QDSSCs) are significant energy-producing devices due to their remarkable capability to growing sunshine and produce many electrons/holes pairs, easy manufacturing, and low cost. However, their power conversion efficiency (4%) is usually worse than that of dye-sensitized solar cells (≤12%); this is mainly due to their narrow absorption areas and the charge recombination happening at the quantum dot/electrolyte and Ti O 2 /electrolyte interfaces. Thus, to raise the power conversion efficiency of QDSSC, new counter electrodes, working electrodes, sensitizers, and electrolytes are required. CdSe thin films have shown great potential for use in photodetectors, solar cells, biosensors, light-emitting diodes, and biomedical imaging systems. This article reviews the CdSe nanomaterials that have been recently used in QDSSCs as sensitizers. Their size, design, morphology, and density all noticeably influence the electron injection efficiency and light-harvesting capacity of these devices. A detailed overview of the development of QDSSCs is presented, including their basic principles, the synthesis methods for their CdSe quantum dots, and the device fabrication processes. Finally, the challenges and opportunities of realizing high-performance CdSe QDSSCs are discussed and some future directions are suggested.

Photocurrent Switching on Electrophoretic CdSe QD Electrodes with Different Ligands

Photoelectrochemical behavior of oleate- and sulfide-capped CdSe QD films fabricated via electrophoretic deposition has been investigated in Na2SO3 aqueous electrolyte. The oleate substitution for sulfide led to considerable increase in photocurrent efficiency. Films of the both types show photocurrent switching under 465-nm light irradiation. The photocurrent direction switching potential strongly depends on the particle size demonstrating negative shift of the potential with size: from 0.0[Formula: see text]V for 2.4[Formula: see text]nm to [Formula: see text][Formula: see text]V for 6.3[Formula: see text]nm.