Single-Exciton Gain and Stimulated Emission across the Infrared Telecom Band from Robust Heavily-doped PbS Colloidal Quantum Dots

Autor: Christodoulou, Sotirios, Ramiro, Iñigo, Othonos, Andreas, Figueroba, Alberto, Dalmases, Mariona, Özdemir, Onur, Pradhan, Santanu, Itskos, Grigorios, Konstantatos, Gerasimos
Rok vydání: 2021
Předmět:
Druh dokumentu: Working Paper
Popis: Materials with optical gain in the infrared are of paramount importance for optical communications, medical diagnostics and silicon photonics. The current technology is based either on costly III-V semiconductors that are not monolithic to silicon CMOS technology or Er-doped fiber technology that does not make use of the full fiber transparency window. Colloidal quantum dots (CQD) offer a unique opportunity as an optical gain medium in view of their tunable bandgap, solution processability and CMOS compatibility. The 8-fold degeneracy of infrared CQDs based on Pb-chalcogenides has hindered the demonstration of low-threshold optical gain and lasing, at room temperature. We demonstrate room-temperature, infrared, size-tunable, band-edge stimulated emission with linewidth of ~14 meV. Leveraging robust electronic doping and charge-exciton interactions in PbS CQD thin films, we reach gain threshold at the single exciton regime representing a four-fold reduction from the theoretical limit of an eight-fold degenerate system, with a net modal gain in excess of 100 cm-1.
Comment: arXiv admin note: substantial text overlap with arXiv:1908.03796
Databáze: arXiv