Hybrid Electrochemical/Chemical Synthesis of Quantum Dots

• Published in: Accounts of chemical research Vol. 33; no. 2; pp. 78 - 86
• Main Author: Penner, Reginald M
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 01.02.2000
• Subjects: Electrochemistry; Metals; Microchemistry; Microscopy, Atomic Force; Oxidation-Reduction; Particle Size; Semiconductors
• ISSN: 0001-4842; 1520-4898
• DOI: 10.1021/ar9702839

The “electrochemical/chemical method” (or “E/C method”) is a new wet chemical method for synthesizing semiconductor quantum dots on graphite surfaces. The E/C synthesis of quantum dots composed of the generic semiconducting salt, MX, typically involves three steps:  (1) electrochemical deposition of nanoparticles of the metal, M°, from a solution of metal ions, M n +; (2) electrochemical oxidation of these metal particles to MO n /2, and; (3) displacement of the oxygen from MO n /2 using HX (for example) to yield nanoparticles of MX. This conversion from metal to metal oxide to metal salt occurs on a particle-by-particle basis; that is, each metal nanoparticle is converted into a semiconductor nanoparticle. E/C-synthesized β-CuI and CdS quantum dots possess many of the attributes of quantum dots synthesized using molecular beam epitaxy, including epitaxial orientation on the graphite surface, a narrow size dispersion, and strong, particle size-tunable photoluminescence. However, the E/C method is faster, cheaper, and applicable to a greater number of materials.