Low‐Threshold Lasing from Copper‐Doped CdSe Colloidal Quantum Wells

• DOI: 10.1002/lpor.202100034
• Publication Date: 2021-05-04T15:42:11Z
• Authors: 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
• Keywords: Population inversion; Nanomaterials; Superradiance

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 their performance in stimulated emission regimes are still elusive. Here, optical gain properties copper‐doped CdSe quantum wells (CQWs) systemically studied with a wide range dopant concentration for first time. This work demonstrates that amplified spontaneous (ASE) threshold CQWs is competing result between biexciton formation, which preferred achieve population inversion, hole trapping stymies inversion. An optimum amount copper dopants enables lowest ASE ≈7 µJ cm −2 , about 8‐fold reduction from undoped (≈58 ) under sub‐nanosecond pulse excitation. Finally, CQW film embedded vertical cavity surface‐emitting laser (VCSEL) structure yields an ultralow lasing 4.1 . Exploiting TMDCNMs may help further boost colloidal‐based lasers.