Stable and efficient high‐power biohybrid light‐emitting diodes (Bio‐HLEDs) using fluorescent proteins (FPs) in photon downconverting filters have not been achieved yet, reaching best efficiencies of 130 lm W−1 stable for >5 h. This is related to the rise of the device temperature (70–80 °C) caused by FP‐motion and quick heat‐transmission in water‐based filters, they lead to a strong thermal emission quenching followed by the quick chromophore deactivation via photoinduced H‐transfer. To tackle both issues at once, this work shows an elegant concept of a new FP‐based nanoparticle, in which the FP core is shielded by a SiO2‐shell (FP@SiO2) with no loss of the photoluminescence figures‐of‐merit over years in foreign environments: dry powder at 25 °C (ambient) or constant 50 °C, as well as suspensions in organic solvents. This enables the preparation of water‐free photon downconverting coatings with FP@SiO2, realizing on‐chip high‐power Bio‐HLEDs with 100 lm W−1 stable for >120 h. Both thermal emission quenching and H‐transfer deactivation are suppressed, since the device temperature holds <40 °C and remote high‐power Bio‐HLEDs exhibit final stabilities of 130 days compared to reference devices with water‐based FP@SiO2 (83 days) and FP‐polymer coatings (>100 h). Hence, FP@SiO2 is a new paradigm toward water‐free zero‐thermal‐quenching biophosphors for first‐class high‐power Bio‐HLEDs.

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.