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

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.

Healthy and stable lighting via single-component white perovskite nanoplates

“…Currently, there are two types of single-component white LHP materials. (1) Self-trapped LHP materials always exhibited broad-band warm-white emission with inevitable deep blue light emission and unalterable color temperature, 18,19,[33][34][35][36][37] which are mainly due to the poor bandgap tunability of selftrapped LHPs. It should be noted that the color temperature is also quite important for applying the light source in different situations.…”

Bi3+ and Sm3+ co-doped Cs2AgInCl6 perovskite microcrystals with co-enhancement of fluorescence emission

“…Apart from these, several successful examples of Eu-, Tb-, Tm-, and Nd-doped Cs 2 AgInCl 6 have been reported. [20][21][22] However, not only the parity-forbidden transition (4f-4f) of lanthanides, but also the weak luminescence of Cs 2 AgInCl 6 due to the Jahn-Teller distortion of the AgCl 6 octahedron 17 limits the practical application. Recently Bi 3+ -Ln 3+ co-doped LDPs have been widely attempted because Bi 3+ is often used as a sensitizer for luminescent lanthanide ions.…”

Special Issue: Rare earth luminescent materials

“…They further explored applications in nondestructive inspections, chemical analyses, anticounterfeiting and night vision lighting. Jin and coworkers discovered that a combination of self-trapped exciton (STE) recombination of Cs 2 AgInCl 6 with Ln 3+ dopant-induced extra light-emitting channels resulted in Vis-NIR (400–2000 nm) ultrabroadband emission from lead-free halide double perovskites (DPs) 16 . The fabricated LEDs featured cost-effective fabrication, compactness, excellent optical performance and extreme long-term stability compared to reported ultrabroadband light sources and showed promise for application in nondestructive spectroscopic analyses and multifunctional lighting.…”