2026-10-10T09:50:12Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34020613 2026-09-29T03:08:16Z category_1 category_915 category_21 category_873 category_46 category_69 portal_63 item_type_6 month_year_09_2026

Deep-Red to Near-Infrared Vertical Cavity Surface-Emitting Lasers from Bipyramidal Weakly Confined Quantum Dots Kerong Jiao (25133899) Honghui Zou (25133902) Jixiang Jiang (25133905) Zhengjie Li (1652869) Kaixin Nie (25133908) Yinjuan Ren (4354678) Yue Wang (65477) Hua Shen (54290) Biophysics Physical Sciences not elsewhere classified Biotechnology Chemical Sciences not elsewhere classified Immunology Inorganic Chemistry vertical cavity surface transient spectroscopy reveals processable gain media gain origin shifts weakly confined cdse infrared region due infrared optical gain intrinsic bandgap limit technologically important deep generation laser devices controlled shell coating naked cdse qds red spectral ranges infrared lasing bulk cdse power devices emitting laser bandgap limitation wavelength beyond threshold deep still challenging mechanistic investigation existing qds emitting lasers demonstrating low chalcogenide qds cds qds canonical metal biexciton recombination auger recombination attractive solution achieves low 720 nm Colloidal quantum dots (QDs) are attractive solution-processable gain media for next-generation laser devices. To date, the canonical metal-chalcogenide QDs have demonstrated superior optical gain across blue, green, and red spectral ranges. However, it is still challenging to access the technologically important deep-red to near-infrared region due to the bandgap limitation of existing QDs. Here, we address the gap by demonstrating low-threshold deep-red to near-infrared optical gain from weakly confined CdSe/CdS QDs. By developing a synthetic strategy toward high-quality bipyramidal CdSe cores and controlled shell coating, we tune the stimulated emission from 660 to 720 nm, a wavelength beyond the intrinsic bandgap limit of bulk CdSe. The mechanistic investigation by transient spectroscopy reveals that the gain origin shifts from biexciton recombination in naked CdSe QDs to electron–hole plasma (EHP) emission in core–shell QDs owing to carrier wave function leakage into the shell. Such weak confinement design demonstrates substantial suppression of Auger recombination in the EHP regime, indicating the potential for high-power devices. Building on these findings, we fabricate a vertical cavity surface-emitting laser that achieves low-threshold deep-red to near-infrared lasing over 690–725 nm. 2026-09-28T00:00:00Z Text Journal contribution 10.1021/acsphotonics.6c01692.s001 https://figshare.com/articles/journal_contribution/Deep-Red_to_Near-Infrared_Vertical_Cavity_Surface-Emitting_Lasers_from_Bipyramidal_Weakly_Confined_Quantum_Dots/34020613 CC BY-NC 4.0