Low-threshold lasing from copper-doped CdSe colloidal quantum wells

Junhong Yu, Manoj Sharma, Mingjie Li, Savas Delikanli, Ashma Sharma, Muhammad Taimoor, Yemliha Altintas, James R. McBride, Thomas Kusserow, Tze-Chien Sum, Hilmi Volkan Demir, Cuong Dang

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25 Citations (Scopus)

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.

Original languageEnglish
Article number2100034
Number of pages7
JournalLaser and Photonics Reviews
Volume15
Issue number6
DOIs
Publication statusPublished - Jun 2021
Externally publishedYes

Keywords

  • amplified spontaneous emission
  • colloidal quantum wells
  • copper doping
  • lasing
  • vertical cavity surface-emitting lasers

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