Compact ultrabroadband light-emitting diodes based on lanthanide-doped lead-free double perovskites

Shilin Jin,Hai Huang,Yuanhui Zheng,Naizhong Jiang,Shaoxiong Wang,Xueyuan Chen,Daqin Chen,Renfu Li,Jidong Lin

doi:10.1038/s41377-022-00739-2

Abstract

Impurity doping is an effective approach to tuning the optoelectronic performance of host materials by imparting extrinsic electronic channels. Herein, a family of lanthanide (Ln3+) ions was successfully incorporated into a Bi:Cs2AgInCl6 lead-free double-perovskite (DP) semiconductor, expanding the spectral range from visible (Vis) to near-infrared (NIR) and improving the photoluminescence quantum yield (PLQY). After multidoping with Nd, Yb, Er and Tm, Bi/Ln:Cs2AgInCl6 yielded an ultrabroadband continuous emission spectrum with a full width at half-maximum of ~365 nm originating from intrinsic self-trapped exciton recombination and abundant 4f–4f transitions of the Ln3+ dopants. Steady-state and transient-state spectra were used to ascertain the energy transfer and emissive processes. To avoid adverse energy interactions between the various Ln3+ ions in a single DP host, a heterogeneous architecture was designed to spatially confine different Ln3+ dopants via a “DP-in-glass composite” (DiG) structure. This bottom-up strategy endowed the prepared Ln3+-doped DIG with a high PLQY of 40% (nearly three times as high as that of the multidoped DP) and superior long-term stability. Finally, a compact Vis–NIR ultrabroadband (400~2000 nm) light source was easily fabricated by coupling the DiG with a commercial UV LED chip, and this light source has promising applications in nondestructive spectroscopic analyses and multifunctional lighting.

Highlights

Ultrabroadband light sources that emit over an extremely wide spectral range are of great interest in many fields, such as photonics, medical treatment, high-capacity optical data communications, ultraprecision metrology, and spectroscopy[1–7]
PL originating from STE recombination for the Cs2AgInCl6 DPs is quite weak, and the corresponding photoluminescence quantum yield (PLQY) is lower than 1%; Bi3+ doping will significantly improve the PL intensity, decay lifetime, and PLQY up to ~25% for STE emission (Fig. S2c, Fig. S2d, Fig. S3)
The optimal Bi3+ nominal doping content is 0.048 mmol (Fig. S3), which corresponds to the actual content of ~15 mol% determined by inductively coupled plasma–mass spectrometry (ICP–MS) (Table S2)

Summary

Introduction

Ultrabroadband light sources that emit over an extremely wide spectral range are of great interest in many fields, such as photonics, medical treatment, high-capacity optical data communications, ultraprecision metrology, and spectroscopy[1–7]. The parity-forbidden 4f–4f transition of Ln3+ leads to weak light absorption, which limits the practical application of these materials. Various lanthanide ions have been successfully doped into the hottest lead-halide perovskite QD (PeQD) lattices to endow them with optical functionality[18–21]. Their use of toxic lead and their poor stability to heat, water, electric fields, and light hamper their commercialization and industrialization on a large scale[22,23]. Cs2AgInCl6 alloyed with 40% Na+ and 0.04% Bi3+ doping emits warm white light with ~86% photoluminescence quantum yield (PLQY) and works beyond 1000 h without obvious PL loss[30]. Several successful examples of DPs doped with Ln3+ ions

Methods

Results

Conclusion