Abstract
The linear and nonlinear (X((2))) optical responses of Langmuir monolayers of organically functionalized silver quantum dots were measured as a continuous function of inter-particle separation under near-ambient conditions. As the distance between metal surfaces was decreased from 12 to ~5 angstroms, both quantum and classical effects were observed in the optical signals. When the separation was less than 5 angstroms, the optical second-harmonic generation (SHG) response exhibited a sharp discontinuity, and the linear reflectance and absorbance began to resemble those of a thin metallic film, indicating that an insulator-to-metal transition occurred. This transition was reversible.
Original language | English |
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Pages (from-to) | 1978-1981 |
Number of pages | 4 |
Journal | Science |
Volume | 277 |
Issue number | 5334 |
DOIs | |
State | Published - Sep 26 1997 |
Externally published | Yes |