Electrically Pumped White-Light-Emitting Diodes Based on Histidine-Doped MoS2 Quantum Dots

Guan-Zhang Lu; Meng-Jer Wu; Tzu-Neng Lin; Chi-Yuan Chang; Wei-Ling Lin; Yi Ting Chen; Chen-Fu Hou; Hao-Jan Cheng; Tai-Yuan Lin; Ji-Lin Shen; Yang-Fang Chen

doi:10.1002/smll.201901908

Electrically Pumped White-Light-Emitting Diodes Based on Histidine-Doped MoS₂ Quantum Dots

Small. 2019 Jul;15(30):e1901908. doi: 10.1002/smll.201901908. Epub 2019 Jun 5.

Authors

Affiliations

¹ Department of Optoelectronic and Materials Technology, National Taiwan Ocean University, Keelung, 202, Taiwan.
² Department of Physics, National Taiwan University, Taipei, 106, Taiwan.
³ Department of Physics and Center for Nanotechnology, Chung Yuan Christian University, ChungLi, 32023, Taiwan.
⁴ Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, 202, Taiwan.

PMID: 31165563
DOI: 10.1002/smll.201901908

Abstract

MoS₂ quantum dots (QDs)-based white-light-emitting diodes (QD-WLEDs) are designed, fabricated, and demonstrated. The highly luminescent, histidine-doped MoS₂ QDs synthesized by microwave induced fragmentation of 2D MoS₂ nanoflakes possess a wide distribution of available electronic states as inferred from the pronounced excitation-wavelength-dependent emission properties. Notably, the histidine-doped MoS₂ QDs show a very strong emission intensity, which exceeds seven times of magnitude larger than that of pristine MoS₂ QDs. The strongly enhanced emission is mainly attributed to nitrogen acceptor bound excitons and passivation of defects by histidine-doping, which can enhance the radiative recombination drastically. The enabled electroluminescence (EL) spectra of the QD-WLEDs with the main peak around 500 nm are found to be consistent with the photoluminescence spectra of the histidine-doped MoS₂ QDs. The enhanced intensity of EL spectra with the current increase shows the stability of histidine-doped MoS₂ based QD-WLEDs. The typical EL spectrum of the novel QD-WLEDs has a Commission Internationale de l'Eclairage chromaticity coordinate of (0.30, 0.36) exhibiting an intrinsic broadband white-light emission. The unprecedented and low-toxicity QD-WLEDs based on a single light-emitting material can serve as an excellent alternative for using transition metal dichalcogenides QDs as next generation optoelectronic devices.

Keywords: MoS2 quantum dots; excitation-wavelength-dependent photoluminescence; microwave-heating; transition metal dichalcogenides; white-light-emitting diodes.

Abstract

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