Low-threshold lasing from copper-doped CdSe colloidal quantum wells
Author(s)
Date
2021-05-04Source Title
Laser & Photonics Reviews
Print ISSN
1863-8880
Electronic ISSN
1863-8899
Publisher
Wiley
Volume
15
Issue
6
Pages
2100034-1 - 2100034-7
Language
English
Type
ArticleItem Usage Stats
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Abstract
Transition metal doped colloidal nanomaterials (TMDCNMs) have recently attracted attention as promising nano-emitters due to dopant-induced properties. However, despite ample investigations on the steady-state and dynamic spectroscopy of TMDCNMs, experimental understandings of their performance in stimulated emission regimes are still elusive. Here, the optical gain properties of copper-doped CdSe colloidal quantum wells (CQWs) are systemically studied with a wide range of dopant concentration for the first time. This work demonstrates that the amplified spontaneous emission (ASE) threshold in copper-doped CQWs is a competing result between the biexciton formation, which is preferred to achieve population inversion, and the hole trapping which stymies the population inversion. An optimum amount of copper dopants enables the lowest ASE threshold of ≈7 µJ cm−2, about 8-fold reduction from that in undoped CQWs (≈58 µJ cm−2) under sub-nanosecond pulse excitation. Finally, a copper-doped CQW film embedded in a vertical cavity surface-emitting laser (VCSEL) structure yields an ultralow lasing threshold of 4.1 µJ cm−2. Exploiting optical gain from TMDCNMs may help to further boost the performance of colloidal-based lasers.
Keywords
Amplified spontaneous emissionColloidal quantum wells
Copper doping
Lasing
Vertical cavity surface-emitting lasers