標題: Thermal Relaxation Spectra for Evaluating Luminescence Quantum Efficiency of CASN:Eu2+ Measured by Balanced-Detection Sagnac-Interferometer Photothermal Deflection Spectroscopy
作者: Chima, Hiromichi
Shiokawa, Naoyuki
Seto, Keisuke
Takahashi, Kohsei
Hirosaki, Naoto
Kobayashi, Takayoshi
Tokunaga, Eiji
交大名義發表
National Chiao Tung University
關鍵字: photothermal deflection spectroscopy;Sagnac interferometer;CASN:Eu2+;luminescence quantum efficiency;photothermal excitation spectrum;photoluminescence excitation spectrum;thermal relaxation spectrum;balanced detection;birefringent crystal CaCO3;thermal diffusion length
公開日期: 1-二月-2020
摘要: Highly sensitive broadband photothermal spectroscopy with a white-light lamp as the excitation source was developed by combining a Sagnac interferometer and balanced detection with a photothermal deflection method. A probe beam was split by a birefringent crystal CaCO3 into signal and reference beams with a balanced intensity. This balanced detection enabled the measurement of photoexcited thermal relaxation spectra of materials in the air over the whole visible range in the weak excitation limit 50 mu W/cm(2). The photothermal excitation spectrum of Eu2+-doped CaAlSiN3 phosphors (CASN:Eu2+) with a high luminescent quantum efficiency was measured to be distinctly different from the photoluminescence excitation spectrum which reflects the absorption spectrum, revealing the thermal relaxation mechanism of the phosphor. Assuming a typical non-radiative relaxation from the higher excited states to the lowest excited state and successively to the ground state, it is demonstrated that the photoluminescence efficiency of the phosphors is readily evaluated simply by comparing the photothermal and photoluminescence excitation spectra.
URI: http://dx.doi.org/10.3390/app10031008
http://hdl.handle.net/11536/154379
DOI: 10.3390/app10031008
期刊: APPLIED SCIENCES-BASEL
Volume: 10
Issue: 3
起始頁: 0
結束頁: 0
顯示於類別:期刊論文