A Study on a Red-emission EuSi2O2N2 Phosphor
- Abstract
- This paper concentrates on red-emission EuSi2O2N2 phosphors which were prepared by solid-state reaction method at 1300℃ under H2 (5%)+N2 (95%) balance gas pressure (1atm, 2atm, 3atm). They were characterized by X-ray diffraction (XRD) patterns. The XRD results indicated that all samples are of a single phase in good agreement with the stand EuSi2O2N2 ICSD card # 41-6046. Compound EuSi2O2N2 crystallizes in a triclinic structure with space group p1 (n1).
Their morphologies were observed by scanning electron microscopy (SEM). The particles size is with diameters ranging from about 500nm up to 5um. The Photoluminescence (PL) and PL excitation (PLE) spectra were measured at room temperature using a 150 watt xeon lamp as an excitation source. The red-emissive EuSi2O2N2 can be efficiently excited in the visible blue light (ex (max) = 520nm) and shows a broad band emission peaking at about 680 nm corresponding to 4f65d1→4f7 transition of Eu2+ .
White LED was fabricated using blue LED (450 nm) with our phosphor, and its mixture of green-emissive CaSc2O4:Ce3+ phosphor or an orange-emissive Sr3SiO5:Eu2+ phosphor. It shows correlated color temperature 4407K, and color rendering index 85.
Our red phosphors showed excellent optical properties and can be applied in the phosphor-converted white LEDs.
- Issued Date
- 2013
- Awarded Date
- 2013. 2
- Type
- Dissertation
- Publisher
- 부경대학교
- Affiliation
- 부경대학교 대학원
- Department
- 대학원 이미지시스템공학과
- Advisor
- 김종수
- Table Of Contents
- CONTENTS
LIST OF TABLES iii
LIST OF FIGURES iv
ABSTRACT vi
1. INTRODUCTION 1
2. THEORY AND ANALYSIS 6
2.1. The Rare Earth Ions (4f-5d and Charge-Transfer Transitions) 6
2.2. Luminescent properties of Eu2+ ion 7
2.3 The crystal structure of EuSi2O2N2 phosphor 9
2.4. Conversion phosphors for white-light LEDs (Solid-state white lighting) 13
3. EXPERIMENTAL PROCEDURE 19
3.1. Solid-State Reaction method to synthesize the EuSi2O2N2 phosphor 19
3.2. Measurements of phosphor properties 21
4. RESULTS AND DISCUSSION 24
4.1. X-ray diffraction patterns and Raman spectrum of red and yellow EuSi2O2N2 24
4.1.1 X-ray diffraction patterns of red EuSi2O2N2 27
4.2. Excitation and emission spectra of red and yellow EuSi2O2N2 28
4.2.1 Luminescence properties of red EuSi2O2N2 31
4.3. Morphology analysis of red EuSi2O2N2 phosphor 39
4.4. Red LED based on EuSi2O2N2 phosphor 40
4.5. White LEDs based on EuSi2O2N2&Sr3SiO5:Eu2+&CaSc2O4:Ce3+ phosphors 41
5. CONCLUSIONS 44
6. REFERENCES 45
7. ACKNOWLEDGEMENTS 49
- Degree
- Master
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