# High-Quantum-Yield [Eu(Phen)2(NO3)3] Phosphor Exhibiting Zero Thermal Quenching under Real Operating Conditions (30–150 °C)

## TL;DR

This paper introduces a new europium-based phosphor that maintains strong red light emission without losing efficiency when heated up to 150°C.

## Contribution

The first demonstration of zero thermal quenching in [Eu(Phen)2(NO3)3] under real operating temperatures.

## Key findings

- The complex shows a high photoluminescence quantum yield of 96% and a long luminescence lifetime of 1.096 ms.
- It exhibits deep-red emission with 99% color purity and stable CIE chromaticity coordinates (0.66, 0.33).
- The phosphor shows no thermal quenching between 30–150 °C due to suppressed back-energy transfer.

## Abstract

In this study, we
present the first investigation of
the temperature-dependent
luminescence properties of the [Eu­(Phen)2(NO3)3] complex across the 30–150 °C range. The
coordination environment, thermal stability, and structural analysis
of the complex were studied by Fourier-transform infrared spectroscopy,
thermogravimetric analysis, and powder X-ray diffraction techniques.
Photoluminescence studies under excitation at 350 and 396 nm revealed
the characteristic Eu3+ emission arising from the 5D0 → 7F
J
(J = 1–4) transitions. Additionally,
the complex exhibits a long luminescence lifetime (τ = 1.096
± 0.001 ms) and a high photoluminescence quantum yield (Φ
= 96%) with λexc = 350 nm. The photometric analysis
confirms deep-red emission with 99% color purity and CIE 1931 chromaticity
coordinates (x, y) = (0.66, 0.33).
Notably, the [Eu­(Phen)2(NO3)3] complex
exhibits zero thermal quenching over the temperature range, which
could be attributed to the effective suppression of thermally activated
back-energy transfer. These results demonstrate exceptional thermal
robustness, highlighting its potential for thermally stable red-emitting
optical applications.