Ultra-broad near-infrared photoluminescence from crystalline (K-crypt)2Bi2 containing [Bi2]2- dimers

TL;DR

This paper reports the discovery of ultra-broad near-infrared photoluminescence in a crystalline bismuth compound, revealing new insights into Bi-related emission mechanisms and expanding potential applications in optical materials.

Contribution

First demonstration of near-infrared PL in (K-crypt)2Bi2 with [Bi2]2+ dimers, providing new understanding of Bi-related luminescence mechanisms.

Findings

PL peaks at 1190 nm with 212 nm FWHM

Inherent electronic transitions of [Bi2]2+ responsible for PL

Implications for Bi-based optical materials

Abstract

For the first time, we report that a single crystal of (K-crypt)2Bi2 containing [Bi2]2+ displays ultra-broad near-infrared photoluminescence (PL) peaking at around 1190 nm and having a full width at the half maximum of 212 nm, stemming from the inherent electronic transitions of [Bi2]2+.The results not only add to the number of charged Bi species with luminescence, but also deepen the understanding of Bi-related near-infrared emission behavior and lead to the reconsideration of the fundamentally important issue of Bi-related PL mechanisms in some material systems such as bulk glasses, fibers, and conventional optical crystals.