Second harmonic generation in microcrystallite films of ultrasmall Si nanoparticles

被引：59

作者：

Nayfeh, MH ^{[1
]}

Akcakir, O ^{[1
]}

Belomoin, G ^{[1
]}

Barry, N ^{[1
]}

Therrien, J ^{[1
]}

Gratton, E ^{[1
]}

机构：

[1] Univ Illinois, Dept Phys, Urbana, IL 61801 USA

来源：

APPLIED PHYSICS LETTERS | 2000年 / 77卷 / 25期

关键词：

D O I：

10.1063/1.1334945

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

We dispersed crystalline Si into a colloid of ultrasmall nano particles (similar to1 nm), and reconstituted it into microcrystallites films on device-quality Si. The film is excited by near-infrared femtosecond two-photon process in the range 765-835 nm, with incident average power in the range 15-70 mW, focused to similar to1 mum. We have observed strong radiation at half the wavelength of the incident beam. The results are analyzed in terms of second-harmonic generation, a process that is not allowed in silicon due to the centrosymmetry. Ionic vibration of or/and excitonic self-trapping on novel radiative Si-Si dimer phase, found only in ultrasmall nanoparticles, are suggested as a basic mechanism for inducing anharmonicity that breaks the centrosymmetry. (C) 2000 American Institute of Physics. [S0003- 6951(00)05452-8].

引用

页码：4086 / 4088

页数：3

共 16 条

[1] Detection of luminescent single ultrasmall silicon nanoparticles using fluctuation correlation spectroscopy [J].