Investigation of Exciton Recombination Zone in Quantum Dot Light-Emitting Diodes Using a Fluorescent Probe

Huang, Xiaoyu1,2; Zhang, Heng1; Xu, Dingxin1; Wen, Feng2; Chen, Shuming1

2017-08-23

10.1021/acsami.7b08574

ACS Applied Materials & Interfaces   影响因子和分区

1944-8244

1944-8252

Exciton recombination zone, where the photons are generated, can greatly affect the performance, such as the efficiency and color purity, of the quantum dot (QD) light-emitting diodes (QLEDs). To probe the exciton recombination zone, 4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) is doped into the charge transport layer as a fluorescent sensor; by monitoring the Forster resonant energy transfer (FRET) between QD and DCJTB, the location of the recombination zone can be determined. It is found that the electron transport layer (ETL) has a great impact on the recombination zone. For example, in QLEDs with ZnMgO ETL, the recombination zone is near the interface of the QD/hole transport layer (HTL) and is shifted to the interface of the QD/ETL as the driving voltage is increased, whereas in devices with 1,3,5-tris(2-N-phenylbenzimidazolyl) benzene (TPBi) ETL, the recombination zone is close to the interface of the QD/ETL and moved to the interface of the QD/HTL with the increase in the driving voltage. Our results can also clarify the light emission mechanism in QLEDs. In devices with ZnMgO ETL, the emission is dominated by the direct charge recombination, whereas in devices with TPBi ETL, the emission is contributed by both FRET and direct charge recombination. Our studies suggest that fluorescent probe can be a powerful tool for investigating the exciton recombination zone, light emission mechanism, and other fundamental processes in QLEDs.

quantum dot light-emitting diodes exciton recombination zone fluorescent probe Forster resonant energy transfer direct charge recombination

SCI ; EI

英语

第一 ; 通讯

Shenzhen Peacock Plan[KQTD2015071710313656]

Science & Technology - Other Topics ; Materials Science

Nanoscience & Nanotechnology ; Materials Science, Multidisciplinary

WOS:000408518800052

AMER CHEMICAL SOC

20173504088689

Diodes ; Electron transport properties ; Energy transfer ; Excitons ; Fluorescence spectroscopy ; Forster resonance energy transfer ; Light ; Light emitting diodes ; Magnesium compounds ; Nanocrystals ; Semiconductor quantum dots ; Zinc compounds

Semiconductor Devices and Integrated Circuits:714.2 ; Light/Optics:741.1 ; Optical Devices and Systems:741.3 ; Nanotechnology:761

Web of Science

1.Southern Univ Sci & Technol, Dept Elect & Elect Engn, Shenzhen 518055, Peoples R China
2.Hainan Univ, Dept Mat & Chem Engn, Key Lab Adv Mat Trop Isl Resources, Minist Educ, Haikou 570228, Hainan, Peoples R China

Huang, Xiaoyu,Zhang, Heng,Xu, Dingxin,et al. Investigation of Exciton Recombination Zone in Quantum Dot Light-Emitting Diodes Using a Fluorescent Probe[J]. ACS Applied Materials & Interfaces,2017,9(33):27809-27816.

Huang, Xiaoyu,Zhang, Heng,Xu, Dingxin,Wen, Feng,&Chen, Shuming.(2017).Investigation of Exciton Recombination Zone in Quantum Dot Light-Emitting Diodes Using a Fluorescent Probe.ACS Applied Materials & Interfaces,9(33),27809-27816.

Huang, Xiaoyu,et al."Investigation of Exciton Recombination Zone in Quantum Dot Light-Emitting Diodes Using a Fluorescent Probe".ACS Applied Materials & Interfaces 9.33(2017):27809-27816.