TY - JOUR
T1 - Electrically control amplified spontaneous emission in colloidal quantum dots
AU - Yu, Junhong
AU - Shendre, Sushant
AU - Koh, Weon kyu
AU - Liu, Baiquan
AU - Li, Mingjie
AU - Hou, Songyan
AU - Hettiarachchi, Chathuranga
AU - Delikanli, Savas
AU - Hernández-Martínez, Pedro
AU - Birowosuto, Muhammad Danang
AU - Wang, Hong
AU - Sum, Tze Chien
AU - Demir, Hilmi Volkan
AU - Dang, Cuong
N1 - Funding Information:
We would like to acknowledge the financial support from the Singapore Ministry of Education AcRF Tier-1 grant (MOE-2017-T1-002-142). We are also grateful to acknowledge the financial support from the Singapore National Research Foundation under the program NRF-NRFI2016-08; the Competitive Research Program NRF-CRP14-2014-03; and the Singapore Agency for Science, Technology and Research (A*STAR) SERC Pharos Program under grant no. 152 73 00025. Author contributions: C.D. initiated the idea and led, supervised, and contributed to all aspects of the research. H.V.D. initiated and supervised the CQD synthesis and capacitor device fabrication. J.Y., H.V.D., and C.D. wrote the manuscript. J.Y., S.S., and B.L. fabricated the device. J.Y. performed the ASE measurements and the steady-state absorbance measurement. J.Y., S.H., and M.D.B. performed the PL dynamics measurement. M.L. conducted the fluence-dependent lifetime measurement. J.Y. and C.D. conducted the kinetic model simulation. S.S. and S.D. synthesized the CdSe/CdS/ZnS CQDs. P.H.-M. conducted the COMSOL simulation. C.H., W.-k.K., and J.Y. performed the SEM and TEM measurements. T.C.S. and H.W. discussed the results and provided the technical advice. All authors discussed the results,
Publisher Copyright:
Copyright © 2019 The Authors, some rights reserved;
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2019/10/25
Y1 - 2019/10/25
N2 - Colloidal quantum dots (CQDs) are highly promising materials for light amplification thanks to their efficient photoluminescence, tunable emission wavelength and low-cost synthesis. Unfortunately, CQDs are suffering from band-edge state degeneracy which demands multiple excitons to achieve population inversion. As a result, non-radiative Auger recombination increases the lasing threshold and limits the gain lifetime. Here, benefiting from the negative charging, we demonstrate that the amplified spontaneous emission (ASE) threshold is controllable in a device where CQD film is exposed to an external electric field. Specifically, singly charged CQDs lower the threshold due to the preexisting electron in the conduction band, while strongly enhanced Auger recombination in doubly charged CQDs stymies the ASE. Experimental results and kinetic equation model show that ASE threshold reduces 10% even if our device only charges ~17% of the CQD population. Our results open new possibilities for controlling exciton recombination dynamics and achieving electrically pumped CQD lasers.
AB - Colloidal quantum dots (CQDs) are highly promising materials for light amplification thanks to their efficient photoluminescence, tunable emission wavelength and low-cost synthesis. Unfortunately, CQDs are suffering from band-edge state degeneracy which demands multiple excitons to achieve population inversion. As a result, non-radiative Auger recombination increases the lasing threshold and limits the gain lifetime. Here, benefiting from the negative charging, we demonstrate that the amplified spontaneous emission (ASE) threshold is controllable in a device where CQD film is exposed to an external electric field. Specifically, singly charged CQDs lower the threshold due to the preexisting electron in the conduction band, while strongly enhanced Auger recombination in doubly charged CQDs stymies the ASE. Experimental results and kinetic equation model show that ASE threshold reduces 10% even if our device only charges ~17% of the CQD population. Our results open new possibilities for controlling exciton recombination dynamics and achieving electrically pumped CQD lasers.
UR - http://www.scopus.com/inward/record.url?scp=85074564463&partnerID=8YFLogxK
U2 - 10.1126/sciadv.aav3140
DO - 10.1126/sciadv.aav3140
M3 - Journal article
C2 - 31692653
AN - SCOPUS:85074564463
SN - 2375-2548
VL - 5
JO - Science advances
JF - Science advances
IS - 10
M1 - eaav3140
ER -