Modulated Fluorescence of Colloidal Quantum Dots Embedded in a Porous Alumina Membrane

• Published in: The journal of physical chemistry. B Vol. 117; no. 45; pp. 14151 - 14156
• Main Authors: Xu, Hao, Li, Li, Manneberg, Otto, Russom, Aman, Gylfason, Kristinn B, Brismar, Hjalmar, Fu, Ying
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 14.11.2013
• Subjects: Aluminum oxide; Aluminum Oxide - chemistry; Analytisk kemi; Atom- och molekylfysik och optik; Cadmium Compounds - chemistry; Colloidal quantum dots; Colloids; Colloids - chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electrons; Emittance; Exact sciences and technology; Excitation; Finite difference time domain simulations; Fluorescence; Fluorescence peak; Fluorescence spectra; Fysik; Heating; Kemi; Membranes; Naturvetenskap; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Photoexcited electrons; Photonic band structures; Photons; Physics; Porosity; Porous alumina membranes; Quantum dots; Quantum Dots - chemistry; Selenium Compounds - chemistry; Spectral feature; Spectrometry, Fluorescence; Sulfides - chemistry; Zinc Compounds - chemistry; Aluminium oxide; Quantum dots; Porous materials; Fluorescence; Excited states; Cadmium sulfide; Spectral line shift; Cadmium selenides; Zinc sulfide; Excitons; Time domain method; Photonic band; Colloidal crystals; Finite difference method
• ISSN: 1520-6106; 1520-5207; 1520-5207
• DOI: 10.1021/jp409132e

The fluorescence spectrum of CdSe core-CdS/ZnS shell colloidal quantum dots (QDs) embedded in porous alumina membrane was studied. Small peaks, superimposed on the principal QD fluorescence spectrum, were observed. Finite-difference time-domain simulation indicates that the QD point radiation emitting from within the membrane is strongly modulated by the photonic band structure introduced by the membrane pores, leading to the observed fine spectral features. Moreover, the principal QD fluorescence peak red-shifted when the optical excitation power was increased, which is attributed to QD material heating due to emitted phonons when the photoexcited electron and hole relax nonradiatively from high-energy states to the ground exciton state before fluorescence.