Effects of the annealing temperature on the structure and up-conversion photoluminescence of ZnO film

doi:10.1016/j.jmst.2018.05.018

Abstract

Abstract:

The up-conversion film is being tried to increase the photoelectric conversion efficiency of the silicon solar cell. To improve the efficiency of the photoluminescence film, the effects of the annealing temperature were investigated on the structure and photoluminescence of the ZnO up-conversion film, which was prepared using the sol-gel method and the spin-coating technique. The results show that the organic compounds and water in the ZnO film were completely eliminated when the annealing temperature reached 500?°C. The crystallinity of film is improved and the average grain size continuously increases as increasing the annealing temperature. The transmittance in the wavelength range of 400-2000?nm continuously increases as the annealing temperature increases from 500?°C to 700?°C, whilst it decreases first and then increases as the annealing temperature increases from 800?°C to 1000?°C. When the film is excited with a laser of 980?nm, there are two intense emission bands in the up-conversion emission spectra, 542-nm green light and 660-nm red light, corresponding to Ho³⁺: ⁵S₂/⁵F₄?→?⁵I₈?and ⁵F₅?→?⁵I₈ transitions, respectively. In addition, the intensity of up-conversion luminescence for the film increases first and then decreases with the increase of the annealing temperature. When the annealing temperature is at 900?°C, the film consists of small round compact particles with a high degree of crystallization, reaching maximum up-conversion intensity of the film.

Key words: Photoluminescence, Up-conversion, Annealing, Sol-gel, ZnO film

Xiaoqi Meng, Changjiang Zhao, Boxu Xu, Pei Wang, Juncheng Liu. Effects of the annealing temperature on the structure and up-conversion photoluminescence of ZnO film[J]. J. Mater. Sci. Technol., 2018, 34(12): 2392-2397.

Figures/Tables 7

Fig. 1. Thermo gravimetric analysis curves of the ZnO gel.

Fig. 2. Effect of the annealing temperature on the surface morphologies of the films.

Fig. 3. Effect of annealing temperature on the XRD patterns of ZnO films.

Table 1 FWHMs of the diffraction peaks and the average grain sizes of ZnO films.

Annealing temperature	Grain size (nm)	FWHMs
Annealing temperature	Grain size (nm)	(100)	(002)	(101)
700?°C	23.9	0.429	0.587	0.570
800?°C	23.0	0.319	0.403	0.341
900?°C	34.9	0.225	0.325	0.236
1000?°C	38.5	0.224	0.284	0.245

Fig. 4. Effect of the annealing temperature on the transmission spectra of the ZnO films.

Fig. 5. Effect of the annealing on the up-conversion spectra of ZnO films (a) Green emission; (b) Red emission.

Fig. 6. Energy level diagram of Yb3+-Ho3+ co-doped in ZnO film as well as the up-conversion mechanisms.

References

[1]	A. Shalav, B. Richards, M. Green, Sol. Energy Mater. Sol. Cells 91 (2007)829-842.
[2]	A. Pan, C. Ca?izo, E. Cánovas, N. Santos, J. Leit?o, A. Luque, Sol. Energy Mater.Sol. Cells 94 (2010)1923-1926.
[3]	C. Strümpel, M. Mccann, G. Beaucarne, V. Arkhipov, A. Slaoui, V. ?vr?ek, C.Ca?izo, I. Tobias, Sol. Energy Mater. Sol. Cells 91 (2007)238-249.
[4]	A. Shalav, B. Richards, T. Trupke, K. Kr?mer, H. Güdel, Appl. Phys. Lett. 86(2005) 013505.
[5]	W. Zhang, J. Lin, Y. Jia, S. Zhang, J. Zhao, G. Sun, S. Ye, J. Ren, L. Rong,Spectrochim. Acta A 134 (2015) 388-398.
[6]	H. Zheng, B. Chen, H. Yu, X. Li, J. Zhang, J. Sun, L. Tong, Z. Wu, H. Zhong, R. Hua,H. Xia, Sensor. Actuat. B-Chem. 234(2016) 286-293.
[7]	H. Wang, X. Yuan, H. Wang, X. Chen, Z. Wu, L. Jiang, W. Xiong, G. Zeng, Appl.Catal. B-Environ. 193(2016) 36-46.
[8]	C. Wang, H. Xia, Z. Feng, Z. Zhang, D. Jiang, X. Gu, Y. Zhang, B. Chen, H.C. Jiang, J. Alloys Compd. 686(2016) 816-822.
[9]	Y. Zhu, S. Cui, Y. Wang, M. Liu, C. Lu, A. Mishra, W. Xu, Nanotechnology 27(2016) 405202.
[10]	Y. Zhao, Y. Ge, X. Zhang, Y. Zhao, H. Zhou, J. Li, H. Jin, J. Alloys Compd. 683(2016) 171-177.
[11]	Z. Liu, K. Hu, J. Ouyang, Y. Jin, J. Alloys Compd. 683(2016) 470-474.
[12]	G. Li, J. Mater. Sci.-Mater. Electron. 27(2016) 11012-11016.
[13]	S. Li, S. Ye, T.H. Liu, H.Y. Wang, D.P. Wang, J. Alloys Compd. 658(2016) 85-90.
[14]	T. Na, Acta Phys. Sin-ch Ed. 54(2005) 4433-4438.
[15]	W. Que, X. Hu, A. Uddin, W. Liu, Mater. Lett. 59(2005) 1614-1618.
[16]	H. Akazawa, H. Shinojima, Mater. Sci. Eng. B 189 (2014)38-44.
[17]	Y. Wang, P. Duan, J. Ning, L. Zhang, J. Deng, Chin. Opt. Lett. 13(2015) 70-73.
[18]	Y. Xue, Y. Guan, J. Dalian Jiaotong Univ. 33(2012) 57-61 (in Chinese).
[19]	X. Li, Q. Nie, S. Dai, T. Xu, L. Lu, X. Zhang, J. Alloys Compd. 454(2008) 510-514.
[20]	Y. Ledemi, D. Manzani, S. Ribeiro, Y. Messaddeq, Opt. Mater. 33(2011)1916-1920.
[21]	M.Y. Ding, C.H. Lu, W.J. Huang, C.F. Jiang, Y.R. Ni, Z.Z. Xu, J. Inorg. Mater. 28(2013) 146-152.
[22]	B.M. Walsh, K.E. Murray, N.P. Barnes, J. Appl. Phys. 91(2002) 11-17.