An Upper Bound to Carrier Multiplication Efficiency in Type II Colloidal Quantum Dots

被引：72

作者：

Gachet, David ^{[1
]}

Avidan, Assaf ^{[1
]}

Pinkas, Iddo ^{[2
]}

Oron, Dan ^{[1
]}

机构：

[1] Weizmann Inst Sci, Dept Phys Complex Syst, IL-76100 Rehovot, Israel

[2] Weizmann Inst Sci, Dept Plant Sci, IL-76100 Rehovot, Israel

来源：

NANO LETTERS | 2010年 / 10卷 / 01期

关键词：

Colloidal quantum dots; carrier multiplication; type-II band alignment; MULTIPLE EXCITON GENERATION; NANOCRYSTALS; PBSE; LIMITS; CDSE;

D O I：

10.1021/nl903172f

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

We experimentally investigate carrier multiplication (CM) in type II CdTe/CdSe quantum dot (QD) heterostructures by the means of a simple and robust subnanosecond transient photoluminescence spectroscopy setup. Experimental conditions were set to minimize the blurring of the CM signature by extraneous effects. The extracted photon energy threshold for CM is consistent with previous studies in CdSe and CdTe QDs (around 2.65 times the type II energy band gap) and we can infer an upper bound to CM yield. This study indicates that, while CM is probably present in type II QD heterostructures below the CM threshold for each constituent separately, it exhibits only a modest yield.

引用

页码：164 / 170

页数：7

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