Abrupt Size Partitioning of Multimodal Photoluminescence Relaxation in Monodisperse Silicon Nanocrystals

被引：34

作者：

Brown, Samuel L. ^{[1
]}

Miller, Joseph B. ^{[1
,3
]}

Anthony, Rebecca J. ^{[2
,4
]}

Kortshagen, Uwe R. ^{[2
]}

Kryjevski, Andrei ^{[1
]}

Hobbie, Erik K. ^{[1
]}

机构：

[1] North Dakota State Univ, Fargo, ND 58108 USA

[2] Univ Minnesota, Minneapolis, MN 55455 USA

[3] Rice Univ, Houston, TX 77005 USA

[4] Michigan State Univ, E Lansing, MI 48824 USA

来源：

ACS NANO | 2017年 / 11卷 / 02期

基金：

美国国家科学基金会;

关键词：

silicon nanocrystals; photoluminescence; quantum confinement; surface effects; AMORPHOUS SURFACE-LAYER; ULTRAFAST PHOTOLUMINESCENCE; QUANTUM YIELD; ATMOSPHERIC-PRESSURE; OPTICAL-PROPERTIES; NANOPARTICLES; LUMINESCENCE; TEMPERATURE; ULTRACENTRIFUGATION; PASSIVATION;

D O I：

10.1021/acsnano.6b07285

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Intrinsic constraints on efficient photoluminescence (PL) from smaller alkene-capped silicon nano crystals (SiNCs) put limits on potential applications, but the root cause of such effects remains elusive. Here, plasma-synthesized colloidal SiNCs separated into monodisperse fractions reveal an abrupt size-dependent partitioning of multilevel PL relaxation, which we study as a function of temperature. Guided by theory and simulation, we explore the potential role of resonant phonon interactions with "minigaps" that emerge in the electronic density of states (DOS) under strong quantum confinement. Such higher order structures can be very sensitive to SiNC surface chemistry, which we suggest might explain the common implication of surface effects in both the emergence of multimodal PL relaxation and the loss of quantum yield with decreasing nanocrystal size. Our results have potentially profound implications for optimizing the radiative recombination kinetics and quantum yield of smaller ligand-passivated SiNCs.

引用

页码：1597 / 1603

页数：7

共 54 条

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