Quantum Confinement in Size-Selected, Surface-Oxidized Silicon Nanocrystals

The dynamics and spectroscopy of silicon nanocrystals that emit at visible wavelengths were analyzed. Size-selective precipitation and size-exclusion chromatography cleanly separate the silicon nanocrystals from larger crystallites and aggregates and provide direct evidence for quantum confinement in luminescence. Measured quantum yields are as high as 50 percent at low temperature, principally as a result of efficient oxide passivation. Despite a 0.9—electron-volt shift of the band gap to higher energy, the nanocrystals behave fundamentally as indirect gap materials with low oscillator strength.

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

[2]  H. Stolz,et al.  Resonant Raman scattering and luminescence from size-quantized indirect exciton states in AgBr microcrystals , 1993 .

[3]  Jonathan K. M. Chun,et al.  Proton Gated Emission from Porous Silicon , 1993 .

[4]  L. Canham,et al.  Identification of radiative transitions in highly porous silicon , 1993 .

[5]  Louis E. Brus,et al.  A luminescent silicon nanocrystal colloid via a high-temperature aerosol reaction , 1993 .

[6]  H. Weller.  Colloidal Semiconductor Q‐Particles: Chemistry in the Transition Region Between Solid State and Molecules , 1993 .

[7]  Takeda,et al.  Theory of the quantum confinement effect on excitons in quantum dots of indirect-gap materials. , 1992, Physical review. B, Condensed matter.

[8]  Christophe Delerue,et al.  Electronic structure and optical properties of silicon crystallites: Application to porous silicon , 1992 .

[9]  V. Petrova-Koch,et al.  Rapid‐thermal‐oxidized porous Si−The superior photoluminescent Si , 1992 .

[10]  Muller,et al.  Mechanisms of visible-light emission from electro-oxidized porous silicon. , 1992, Physical review. B, Condensed matter.

[11]  G. Mclendon,et al.  Effect of size restriction on the static and dynamic emission behavior of silver bromide , 1992 .

[12]  T. D. Harris,et al.  Luminescence and structural study of porous silicon films , 1992 .

[13]  L. Brus,et al.  Quantum crystallites and nonlinear optics , 1991 .

[14]  Volker Lehmann,et al.  Porous silicon formation: A quantum wire effect , 1991 .

[15]  Norman Herron,et al.  Nanometer-sized semiconductor clusters: materials synthesis, quantum size effects, and photophysical properties , 1991 .

[16]  L. Canham.  Silicon quantum wire array fabrication by electrochemical and chemical dissolution of wafers , 1990 .

[17]  A. Henglein,et al.  Small-particle research: physicochemical properties of extremely small colloidal metal and semiconductor particles , 1989 .

[18]  Louis E. Brus,et al.  Size effects in the excited electronic states of small colloidal CdS crystallites , 1984 .

[19]  A. A. Studna,et al.  Dielectric functions and optical parameters of Si, Ge, GaP, GaAs, GaSb, InP, InAs, and InSb from 1.5 to 6.0 eV , 1983 .