Origins of Low Quantum Efficiencies in Quantum Dot LEDs

被引：160

作者：

Bozyigit, Deniz ^{[1
]}

Yarema, Olesya ^{[1
]}

Wood, Vanessa ^{[1
]}

机构：

[1] ETH, Lab Nanoelect, Dept Informat Technol & Elect Engn, Zurich, Switzerland

来源：

ADVANCED FUNCTIONAL MATERIALS | 2013年 / 23卷 / 24期

基金：

瑞士国家科学基金会;

关键词：

light-emitting devices; quantum dots; core; shell nanoparticles; luminescence; LIGHT-EMITTING-DIODES; CDSE NANOCRYSTALS; ELECTRIC-FIELD; SHELL-THICKNESS; BLINKING; SEMICONDUCTORS; CRYSTALLITES; INTENSITY;

D O I：

10.1002/adfm.201203191

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The promise for next generation light-emitting device (LED) technologies is a major driver for research on nanocrystal quantum dots (QDs). The low efficiencies of current QD-LEDs are often attributed to luminescence quenching of charged QDs through Auger-processes. Although new QD chemistries successfully suppress Auger recombination, high performance QD-LEDs with these materials have yet to be demonstrated. Here, QD-LED performance is shown to be significantly limited by the electric field. Experimental field-dependent photoluminescence decay studies and tight-binding simulations are used to show that independent of charging, the electric field can strongly quench the luminescence of QD solids by reducing the electron and hole wavefunction overlap, thereby lowering the radiative recombination rate. Quantifying this effect for a series of CdSe/CdS QD solids reveals a strong dependence on the QD band structure, which enables the outline of clear design strategies for QD materials and device architectures to improve QD-LED performance.

引用

页码：3024 / 3029

页数：6

共 31 条

[1] Field induced photoluminescence quenching and enhancement of CdSe nanocrystals embedded in SiO2 [J].

Achtstein, A. W. ;

Karl, H. ;

Stritzker, B. .

APPLIED PHYSICS LETTERS, 2006, 89 (06)

[2] Electronic and excitonic processes in light-emitting devices based on organic materials and colloidal quantum dots [J].

Anikeeva, P. O. ;

Madigan, C. F. ;

Halpert, J. E. ;

Bawendi, M. G. ;

Bulovic, V. .

PHYSICAL REVIEW B, 2008, 78 (08)

[3] Study of field driven electroluminescence in colloidal quantum dot solids [J].

Bozyigit, Deniz ;

Wood, Vanessa ;

Shirasaki, Yasuhiro ;

Bulovic, Vladimir .

JOURNAL OF APPLIED PHYSICS, 2012, 111 (11)

[4] ELECTRIC-FIELD ASSISTED DISSOCIATION OF CHARGE-TRANSFER STATES AS A MECHANISM OF PHOTOCARRIER PRODUCTION [J].

BRAUN, CL .

JOURNAL OF CHEMICAL PHYSICS, 1984, 80 (09) :4157-4161

[5] Nano-engineered electron-hole exchange interaction controls exciton dynamics in core-shell semiconductor nanocrystals [J].

Brovelli, S. ;

Schaller, R. D. ;

Crooker, S. A. ;

Garcia-Santamaria, F. ;

Chen, Y. ;

Viswanatha, R. ;

Hollingsworth, J. A. ;

Htoon, H. ;

Klimov, V. I. .

NATURE COMMUNICATIONS, 2011, 2

[6] Colloidal quantum-dot light-emitting diodes with metal-oxide charge transport layers [J].

Caruge, J. M. ;

Halpert, J. E. ;

Wood, V. ;

Bulovic, V. ;

Bawendi, M. G. .

NATURE PHOTONICS, 2008, 2 (04) :247-250

[7]

COLVIN VL, 1994, NATURE, V370, P354, DOI 10.1038/370354a0

[8] Suppression of Auger Processes in Confined Structures [J].

Cragg, George E. ;

Efros, Alexander L. .

NANO LETTERS, 2010, 10 (01) :313-317

[9] Quantum-confined stark effect in single CdSe nanocrystallite quantum dots [J].

Empedocles, SA ;

Bawendi, MG .

SCIENCE, 1997, 278 (5346) :2114-2117

[10] Lifetime blinking in nonblinking nanocrystal quantum dots [J].

Galland, Christophe ;

Ghosh, Yagnaseni ;

Steinbrueck, Andrea ;

Hollingsworth, Jennifer A. ;

Htoon, Han ;

Klimov, Victor I. .

NATURE COMMUNICATIONS, 2012, 3

← 1 2 3 4 →