Two‐Color Amplified Spontaneous Emission from Auger‐Suppressed Quantum Dots in Liquids

Journal Article · Fri Dec 08 00:00:00 EST 2023 · Advanced Materials

DOI:https://doi.org/10.1002/adma.202308979· OSTI ID:2229950

Li, Xueyang ^[1]; Du, Jun ^[2]; Zhao, Guohui ^[3]; Zhang, Boyu ^[1]; Livache, Clément ^[4]; Ahn, Namyoung ^[4]; Jia, Yuxi ^[5]; Li, Mingrun ^[6]; Chen, Ying ^[7]; Zhu, Jingyi ^[1]; Guo, Jingwei ^[5]; Klimov, Victor I. ^[4]; Wu, Kaifeng ^[3]

---

1. State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian Liaoning 116023 China
2. State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian Liaoning 116023 China, Nanotechnology and Advanced Spectroscopy Team C‐PCS Chemistry Division Los Alamos National Laboratory Los Alamos NM 87545 USA
3. State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian Liaoning 116023 China, University of Chinese Academy of Sciences Beijing 100049 China
4. Nanotechnology and Advanced Spectroscopy Team C‐PCS Chemistry Division Los Alamos National Laboratory Los Alamos NM 87545 USA
5. University of Chinese Academy of Sciences Beijing 100049 China, CAS Key Laboratory of Chemical Lasers Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian Liaoning 116023 China
6. State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian Liaoning 116023 China
7. CAS Key Laboratory of Chemical Lasers Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian Liaoning 116023 China

Abstract

Colloidal quantum‐dot (QD) lasing is normally achieved in close‐packed solid‐state films, as a high QD volume fraction is required for stimulated emission to outcompete fast Auger decay of optical‐gain‐active multiexciton states. Here a new type of liquid optical‐gain medium is demonstrated, in which compact compositionally‐graded QDs (ccg‐QDs) that feature strong suppression of Auger decay are liquefied using a small amount of solvent. Transient absorption measurements of ccg‐QD liquid suspensions reveal broad‐band optical gain spanning a wide spectral range from 560 (green) to 675 nm (red). The gain magnitude is sufficient to realize a two‐color amplified spontaneous emission (ASE) at 637 and 594 nm due to the band‐edge (1S) and the excited‐state (1P) transition, respectively. Importantly, the ASE regime is achieved using quasicontinuous excitation with nanosecond pulses. Furthermore, the ASE is highly stable under prolonged excitation, which stands in contrast to traditional dyes that exhibit strong degradation under identical excitation conditions. These observations point toward a considerable potential of high‐density ccg‐QD suspensions as liquid, dye‐like optical gain media that feature readily achievable spectral tunability and stable operation under intense photoexcitation.

• Sponsoring Organization: USDOE
• OSTI ID: 2229950
• Journal Information: Advanced Materials, Journal Name: Advanced Materials; ISSN 0935-9648
• Publisher: Wiley Blackwell (John Wiley & Sons)
• Country of Publication: Germany
• Language: English