LUMINESCENCE OF SILICON MATERIALS - CHAINS, SHEETS, NANOCRYSTALS, NANOWIRES, MICROCRYSTALS, AND POROUS SILICON
LUMINESCENCE OF SILICON MATERIALS - CHAINS, SHEETS, NANOCRYSTALS, NANOWIRES, MICROCRYSTALS, AND POROUS SILICON
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DOI：
10.1021/j100065a007
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发表时间：
1994-04-07
影响因子：
--
通讯作者：
BRUS, L
中科院分区：
文献类型：
--
作者：
BRUS, L
单晶硅和多孔硅薄膜在室温下都显示出有效的可见光发光，从而表明将某种形式的光学活性硅基材料引入集成电路加工的可能性。在此背景下，我讨论和分析负责的电子量子尺寸效应和激发态量子物理。在更广泛的背景下，我讨论硅的光学和电子性能作为一个功能的维度和表面化学。随着从反式聚硅烷（1D-Si）通过褶皱片聚硅炔（2D-Si）到金刚石晶格硅（3D-Si）的进展，存在从直接到间接带隙行为的系统进展。在2D-Si中，直接和间接能隙接近简并，并且可以通过表面化学衍生来定制电子性质。可能的是，直接间隙材料可以在羟基异戊烯材料中发现。体3D-Si是显着的，其缓慢的速率的辐射和非辐射的本征激发态衰减。纳米晶Si和多孔Si是间接带隙型材料，其振子强度相对于体Si没有显著增加。发光增加，因为空间限制保持电子和空穴叠加，因为表面非辐射率也非常慢。理论表明，通过诸如应变或纳米有限尺寸的物理效应降低金刚石晶格对称性仅产生3D-Si发光的相对较小的扰动。然而，有限的纳米尺寸可以增加多达1 eV的间接间隙。微晶硅可以是一种高效的光腔。
Both nanocrystal silicon and porous silicon thin films show efficient visible luminescence at room temperature, thus suggesting the possibility of introducing some form of optically active, silicon-based material into integrated circuit processing. In this context, I discuss and analyze the responsible electronic quantum size effects and excited-state photophysics. In a broader context I discuss silicon optical and electronic properties as a function of dimensionality and surface chemistry. As one progresses from trans-polysilane (1D-Si) through puckered sheet polysilyne (2D-Si) to diamond lattice silicon (3D-Si), there is a systematic progression from direct to indirect gap behavior. In 2D-Si the direct and indirect gaps are nearly degenerate, and the electronic properties can be tailored through surface chemical derivatization. It may be that a direct gap material can be found in the hydroxysiloxene materials. Bulk 3D-Si is remarkable for its slow rates of both radiative and nonradiative intrinsic excited-state decay. Nanocrystal Si and porous Si are indirect gap type materials with oscillator strengths that are not markedly increased with respect to bulk Si. Luminescence increases because spatial confinement keeps the electron and hole superimposed and because surface nonradiative rates are also extremely slow. Theory indicates that lowering of the diamond lattice symmetry via physical effects, such as strain or nanometer finite size, creates only a relatively minor perturbation of the 3D-Si luminescence. However, finite nanometer size can increase the indirect gap by as much as 1 eV. Microcrystalline silicon can be an efficient optical cavity.