White-light emission from organics-capped ZnSe quantum dots and application in white-light-emitting diodes

Organics-capped ZnSe quantum dots were synthesized by a colloidal chemical approach using ZnO and Se powder as precursors. The photoluminescence of the specimens showed strong white emission (∼200nm full width at half maximum) in the visible range under ambient conditions. The white emission was attributed to the mixing of blue emission of ZnSe nanocrystals exhibiting quantum confinement effect with green-red emission of radiative deep levels from ZnSe surface strained lattice. Based on organic-capped ZnSe quantum dots, the white-light-emitting diodes were fabricated using a near-UV InGaN chip as the excitation source. The diodes emitted white light with CIE chromaticity coordinates of (0.38 and 0.41) and show great potential for use in lighting applications.

[1]  M. Bawendi,et al.  Synthesis and characterization of nearly monodisperse CdE (E = sulfur, selenium, tellurium) semiconductor nanocrystallites , 1993 .

[2]  Xiaogang Peng,et al.  Epitaxial Growth of Highly Luminescent CdSe/CdS Core/Shell Nanocrystals with Photostability and Electronic Accessibility , 1997 .

[3]  M. Bawendi,et al.  (CdSe)ZnS Core-Shell Quantum Dots - Synthesis and Characterization of a Size Series of Highly Luminescent Nanocrystallites , 1997 .

[4]  Alan J. Heeger,et al.  White light from InGaN/conjugated polymer hybrid light-emitting diodes , 1997 .

[5]  P. Guyot-Sionnest,et al.  Bright UV-Blue Luminescent Colloidal ZnSe Nanocrystals , 1998 .

[6]  Howard W. H. Lee,et al.  Ultraviolet-blue emission and electron-hole states in ZnSe quantum dots , 1999 .

[7]  Philippe Guyot-Sionnest,et al.  n-type colloidal semiconductor nanocrystals , 2000, Nature.

[8]  Xiaogang Peng,et al.  Formation of high-quality CdTe, CdSe, and CdS nanocrystals using CdO as precursor. , 2001, Journal of the American Chemical Society.

[9]  G. Lu,et al.  Green-light-emitting ZnSe nanowires fabricated via vapor phase growth , 2003 .

[10]  Soo-Yeon Seo,et al.  Y 3Al5 O 12 : Ce0.05 Phosphor Coatings on Gallium Nitride for White Light Emitting Diodes , 2003 .

[11]  P. T. Lai,et al.  Efficient white and red light emission from GaN/tris-(8-hydroxyquinolato) aluminum/platinum(II) meso-tetrakis(pentafluorophenyl) porphyrin hybrid light-emitting diodes , 2003 .

[12]  Hee Dong Park,et al.  White light-emitting diodes of GaN-based Sr2SiO4:Eu and the luminescent properties , 2003 .

[13]  Hsueh‐Shih Chen,et al.  Colloidal ZnSe, ZnSe/ZnS, and ZnSe/ZnSeS Quantum Dots Synthesized from ZnO , 2004 .