Fully Biogenic Near‐Infrared Phosphors: Phycobiliproteins and Cellulose at Force Toward Highly Efficient and Stable Bio‐Hybrid Light‐Emitting Diodes

Abstract

Stable/efficient low‐energy emitters for photon down‐conversion in bio‐hybrid light‐emitting diodes (Bio‐HLEDs) are still challenging, as the archetypal fluorescent protein (FP) mCherry has led to the best deep‐red Bio‐HLEDs with poor stabilities: 3 h (on‐chip)/160 h (remote). Capitalizing on the excellent refolding under temperature/pH/chemical stress, high brightness, and high compatibility with polysaccharides of phycobiliproteins (smURFP), first‐class low‐energy emitting Bio‐HLEDs are achieved. They outperform those with mCherry regardless of using reference polyethylene oxide (on‐chip: 24 h vs. 3 h) and new biopolymer hydroxypropyl cellulose (HPC; on‐chip: 44 h vs. 3 h) coatings. Fine optimization of smURFP‐HPC‐coatings leads to stable record devices (on‐chip: 2600 h/108 days) compared to champion devices with perylene diimides (on‐chip: <700 h) and artificial FPs (on‐chip: 35 h). Finally, spectroscopy/computational/thermal assays confirm that device degradation is related to the photo‐induced reduction of biliverdin to bilirubin. Overall, this study pinpoints a new family of biogenic emitters toward superior protein‐based lighting.

Organoboron-Conjugated Homopolymers with Bright Narrowband Near-Infrared Emission

“…NIR light-emitting diodes have received great attention because of their applications in biomedical applications, night vision, surveillance, and optical communications. The strong absorption of red light, high quality NIR emission with high Φ F and small FWHM, together with solution processability of PB-FPO suggest that it can be used as an NIR light converter in LEDs. − This stimulates uses to fabricate NIR OLEDs using PB-FPO to convert visible light from the OLED to invisible NIR light. The solution-processed red OLED device has the configuration of glass/ITO/PEDOT:PSS/PVK/m-MTDATA:RD-3/TMPyPB/LiF/Al (see Figure a), which has been previously reported in the literature.…”

Simple Sol‐Gel Protein Stabilization toward Rainbow and White Lighting Devices

“…performance compared to previous white solid-encapsulated Bio-HLEDs. [27,35,38,[41][42][43][44] Overall, this work opens the door to a very straightforward and effective sol-gel method for FP stabilizations that could be, in addition, extended to other types of proteins and enzymes.…”

“…Capitalizing on these promising results, we further demonstrate their relevance in rainbow and white bio-hybrid lightemitting diodes (Bio-HLEDs). [5] This approach promises to replace rare earth or toxic color down-converting filters (i.e., inorganic phosphors; Ce-doped Y 3 Al 5 O 12 and Cd-based quantum dots) present in commercial white light-emitting diodes by organic [31][32][33][34][35][36][37] and biogenic [27,38,39] phosphors based on artificial emitters and FPs embedded into polymer/epoxy matrices, respectively. As a matter of fact, HLEDs with organic phosphors, such as perylene diimide, boron-dipyrromethene, and iridium(III) complex embedded in polymers, have shown moderate stabilities of a few hundred of hours.…”

“…[35,36,40] However, monochromatic Bio-HLEDs have recently exceed stabilities of ≈3000 h, while white-emitting Bio-HLEDs are still limited by average stabilities of <100 h at low luminous efficiencies <50 lm W −1 . [27,38,41,42] Herein, we show that i) monochromatic Bio-HLEDs containing FP@SiO 2 nanoparticles featured up to ≈15-fold enhanced device stabilities without losing efficiency compared to reference devices with their respective native FPs, and ii) white-emitting Bio-HLEDs with dual-emissive FP@SiO 2 good-perform with a white emission color (x/y CIE color coordinates 0.36/0.36) stable over ≈40 h at luminous efficiency of 60 lm W −1 ; a better-balanced Figure 2. A) Photographs of both mGL@SiO 2 (top) and mCherry@SiO 2 (mCherry) powders under ambient natural light and UV irradiation.…”

Genetically Encoded Oligomerization for Protein‐Based Lighting Devices

“…[7,[26][27][28][29][30][31] Among them, FPs are considered a model of sustainability with respect to their cheap bacterial production, easy recyclability, water-processability, excellent emission merits, and low-cost as high purification levels are not required. [32][33][34][35] In addition, the performance of Bio-HLEDs is becoming more and more appealing with stabilities of >3000 h and efficiencies of >130 lm W −1 at low-power conditions (<50 mW cm −2 photon flux excitation) [7] compared to other devices with traditional organic phosphors: i) perylene diimide-polymer with <700 h@130 lm W −1 , [29] ii) BODIPYs-polymer with <10 h@13 lm W −1 , [31] and iii) Iridium(III) complex-polymer with <1000 h@100 lm W −1 . [30] In contrast, the device stability is typically reduced to <5 min at high-power operation conditions (200 mW cm −2 photon-flux excitation; due to photo-induced heat generation (up to 70 °C) in the color down-converting coating caused by FP motion and efficient heat transfer in a water-rich environment.…”