Emission from Rare-Earth (RE) Ions by the Energy Transfer from ZnO - - PowerPoint PPT Presentation

▶
emission from rare earth re ions by the energy transfer
SMART_READER_LITE
LIVE PREVIEW

Emission from Rare-Earth (RE) Ions by the Energy Transfer from ZnO - - PowerPoint PPT Presentation

Feb 18, 2023 208 likes •523 views

Emission from Rare-Earth (RE) Ions by the Energy Transfer from ZnO Nanocrystals Embedded in SiO 2 Film Kim Minseo Chong Kai Chong, Benedict 1 Table of Contents 1. Introduction 2. Research Aim 3. Methodology 4. Results and Discussion 5.

slide-1
SLIDE 1

Emission from Rare-Earth (RE) Ions by the Energy Transfer from ZnO Nanocrystals Embedded in SiO2 Film

1

Kim Minseo Chong Kai Chong, Benedict

slide-2
SLIDE 2

Table of Contents

1. Introduction

  • 2. Research Aim
  • 3. Methodology
  • 4. Results and Discussion
  • 5. Conclusion

2

slide-3
SLIDE 3

Introduction

3

slide-4
SLIDE 4
  • White-light LEDs

○ Mixing lights from various LEDs ○ Using phosphor to convert light colours

4

Introduction

slide-5
SLIDE 5

How is our research different from these semiconductors?

5

Introduction

slide-6
SLIDE 6
  • Zinc oxide Nanocrystals (ZnO-nc) commonly

used as wide bandgap semiconductors

6

Introduction

  • Potential

application in

  • ptoelectronics

devices

  • Efficient energy transfer from ZnO-nc to

Rare-earth (RE) ions like Europium (III) ions (Eu3+) and Terbium (III) ions (Tb3+)

slide-7
SLIDE 7
  • These samples are fabricated using cost-

effective sol-gel process

  • Relatively simple to fabricate samples

7

Introduction

Sol-Gel Process

slide-8
SLIDE 8
  • Eu3+ ions ⇒ Red
  • Tb3+ ions ⇒ Green
  • ZnO-nc ⇒ Blue

8

Introduction

  • Potentially be used to create white light or

various colours by differing concentrations

  • f ions (RBG components will change)
slide-9
SLIDE 9
  • Most research involve only one RE ion
  • Simple photoluminescence (PL) measurements

○ Focus of paper was on efficiency of energy transfer instead

9

Introduction

  • Lack of research involving combination of two

different RE ions

  • Even

fewer studies done

  • n

varying concentrations of RE ions to obtain different colours of light

slide-10
SLIDE 10

Research Aim

10

slide-11
SLIDE 11
  • Prediction of concentration of RE ions for white

light emission

  • Cost-effective method of production and usage in

display devices

11

Research Aim

slide-12
SLIDE 12

Methodology

12

slide-13
SLIDE 13

13

1931 CIE Diagram

slide-14
SLIDE 14

14

Methodology

X, Y and Z?

  • Tristimulus values associated with the CIE 1931 XYZ

color space

  • Conceptualized as amounts of three primary colors in a

tri-chromatic, additive color model

slide-15
SLIDE 15

15

Results and Discussions

slide-16
SLIDE 16

16

25 points for the combined emission from the two films each incorporated with either Eu3+ or Tb3+.

slide-17
SLIDE 17

17

18 points for the films with Eu3+ and Tb3+ incorporated together.

slide-18
SLIDE 18

18

Graph of x against concentration of Eu3+ and Tb3+ ions

slide-19
SLIDE 19

19

Graph of y against concentration of Eu3+ and Tb3+ ions

slide-20
SLIDE 20

20

Graph of z against concentration of Eu3+ and Tb3+ ions

slide-21
SLIDE 21

21

Polynomial equations relating concentrations of Eu3+ and Tb3+ to x, y and z

slide-22
SLIDE 22

22

  • White light emission for films with Eu3+ and Tb3+

incorporated together → 1.0% of Eu3+ and 4.4% of Tb3+

Results and Discussions

  • Combined white light emission from films with

Eu3+ and Tb3+ incorporated separately → 7.3% of Eu3+ and 9.3% of Tb3+

slide-23
SLIDE 23

23

  • Energy transfer from ZnO-nc to Eu3+ ions is much

more efficient than from ZnO-nc to Tb3+ ions

Results and Discussions

  • Cost effective to incorporate Eu3+ and Tb3+

together as lower concentration of expensive RE ions needed

slide-24
SLIDE 24

24

Conclusion

slide-25
SLIDE 25
  • To improve reliability, we could have used other

methods and cross reference the results

25

Conclusion

  • Could have modelled the emission spectrum of

each sample as a function of concentration of Eu3+ and Tb3+ ions

  • Could have modelled X, Y and Z as a function of

Eu3+ and Tb3+ ions instead of x, y and z

slide-26
SLIDE 26
  • Key exploration in obtaining desired emission

spectrum from experiments and practical uses

26

Conclusion

  • Has substantial potential in industrial light-

emitting and optoelectronics devices

slide-27
SLIDE 27

1. Pita, K.; Baudin, P.; Vu, Q.; Aad, R.; Couteau, C.; Lerondel, G. Annealing temperature and environment effects on zno nanocrystals embedded in sio2: A photoluminescence and tem

  • study. Nanoscale Res. Lett. 2013, 8, 517. (Figure 1)

2. Mangalam, V.; Pita, K. Energy transfer from ZnO nanocrystals to Terbium (3+) ions: A spectral overlap study. n.d. 1-2 3. Mangalam, V.; Pita, K. Energy Transfer Efficiency from ZnO- Nanocrystals to Eu3+ Ions Embedded in SiO2 Film for Emission at 614 nm Nanoscale Res. Lett. 2017, 8, 1-9 4. Mangalam, V.; Pita, K.; Couteau, C. Study of energy transfer mechanism from zno nanocrystals to eu3+ ions. Nanoscale Res.

  • Lett. 2016, 11, 1–9.

5.

  • L. Luo et al. Strong luminescence and efficient energy transfer in

Eu3+/Tb3+- codoped ZnO nanocrystals. Optical Materials, Volume 37, November 2014, Pages 470-475 https://doi.org/10.1016/j.optmat.2014.07. 008

27

References

slide-28
SLIDE 28

28

Thank you!

slide-29
SLIDE 29

29

MATLAB Loop Control Statements

slide-30
SLIDE 30

30