Recycling Polycrystalline Silicon Solar Cells

doi:10.15541/jim20170547

Abstract

Abstract:

Recovering Si material from the degraded solar cells is significant for environmental protection and material recycling. In this tudy, the optimal conditions for recycling degraded solar cells by chemical etching and ultrasonic cleaning were investigated. The samples were tested by EDS, SEM and XPS, The results showed that Al electrodes were completely removed from cells by reaction with 10wt% NaOH solution for 18 min, with less silicon corrosion lost. After that, Ag electrodes were completely exfoliated from the cells by ultrasonic cleaning (40 kHz) for 20 min. Si₃N₄ film was thoroughly eliminated after the cells were etched with 40wt% HF solution for 10 min, which was proved to be the optimal reaction time. A quantitative experiment was performed in this study with 8. 9068 g cells. The results show that the recycling mass of Al electrodes, Ag electrodes and Si wafers are 1.1102 g, 0.0766 g and 7.7169 g, respectively.

Key words: polycrystalline silicon, solar cells, recycle

CLC Number:

TQ174

LI Jia-Yan, CAI Min, WU Xiao-Wei, TAN Yi. Recycling Polycrystalline Silicon Solar Cells[J]. Journal of Inorganic Materials, 2018, 33(9): 987-992.

Figures/Tables 11

Fig. 1 SEM image of rear face of the multicrystalline cell before etched

Fig. 2 EDS analysis of rear faces of multicrystalline cells after etching in 5%, 10% and 15% NaOH solution with different reaction time

Fig. 3 SEM images of rear faces of multicrystalline cells after etching in 5wt% NaOH solution with 9 min (a), 12 min (b), 15 min(c), 8 min (d), 21 min (e) and 24 min (f)

Fig. 4 SEM images of rear faces of multicrystalline cells after etching in 10% NaOH solution with 9 min (a), 12 min (b), 15 min (c), 18 min(d), 21 min (e) and 24 min (f)

Fig. 5 SEM images of rear faces of multicrystalline cells after etching in 15% NaOH solution with 9 min (a), 12 min (b), 15 min (c), 18 min (d), 21 min (e) and 24 min (f)

Fig. 6 EDS analysis of front faces of multicrystalline cells before and after removing the Ag electrodes with different treatments

Fig. 7 SEM images of front face with visible finger (a), front (b) and rear (c) faces of silver finger after ultrasonic cleaning

Fig. 8 XPS analysis of front faces of multicrystalline cells before (a) and after (b) etching

Table 1 The mass of each component of a multicrystalline cell

Component	Solar cell	Si wafer	Al electrode	Ag electrode
Mass/g	8.9068	7.7169	1.1102	0.0766

Fig. 9 Views of a multicrystalline solar cell recovered from damaged cells: front (a) and rear (b) side

Fig. 10 Views of silicon wafers (a) and silver fingers (b) recovered from a multicrystalline solar cell

References 20

[1]	YAN YUN-FEI, ZHANG ZHI-EN, ZHANG LI,et al. Application and utilization technology of solar energy. Acta Energiae Solaris Sinica, 2012, 33(sl): 47-56.
[2]	PARK JONGSUNG, PARK NOCHANG.Wet etching processes for recycling crystalline silicon solar cells from end-of-life photovoltaic modules.RSC Advances, 2014, 4: 34823-34829.
[3]	EWA KLUGMANN-RADZIEMSKA, PIOTR OSTROWSKI, KAZIMERZ DRABCZYK,et al. Experiment validation of crystalline silicon solar cells recycling by thermal and chemical methods. Solar Energy Material and Solar Cells, 2012, 94(12): 2275-2282.
[4]	MCDONALD N C, PEARCE J M.Producer responsibility and recycling solar photovoltaic modules.Energy Policy, 2010, 38(11): 7041-7047.
[5]	VASILIS M, FTHENAKIS. End-of-life management and recycling of PV modules.Energy Policy, 2000, 28(14): 1051-1058.
[6]	吴昊. 高效多晶硅太阳能电池制备工艺研究. 长沙: 湖南大学硕士学位论文, 2014.
[7]	FU MING, ZHOU HONG, HUA KAI-WEI,et al. Aging characteristics of crystalline silicon solar cells. Electronic Components and Materials, 2017, 36(12): 79-83.
[8]	HUANG WEN-HIS, TAO MENG.A Simple Green Process to Recycle Si from Crystalline-Si Solar Cells. Photovoltaic Specialist Conference, 2015IEEE 42nd, IEEE, 2015: 1-4.
[9]	ZHANG LINGEN, XU ZHENMING.Separating and recycling plastic, glass, and gallium from waste solar cell modules by nitrogen pyrolysis and vacuum decomposition.Environmental Science and Technology, 2016, 50: 9242-9250.
[10]	SONG ER-XIAO, ZHANG CHENG-LONG, MA EN,et al. Recovery processing status of waste crystalline silicon solar cell. Journal of Shanghai Polytechnic University, 2017, 34(3): 157-162.
[11]	董莉. 废晶体硅太阳能电池板资源化技术研究. 成都: 西南交通大学硕士学位论文, 2014.
[12]	LUO FU-XIANG, PENG XIAO-CHUN, WU YAN-YU,et al. Research progress of waste crystalline solar cells recycling and dismantling. Environmental Science and Management, 2014, 39(12): 160-163.
[13]	EWA KLUGMANN-RADZIEMSKA, PIOTR OSTROWSKI.Chemical treatment of crystalline silicon solar cells as a method of recovering pure silicon from photovoltaic modules.Renewable Energy, 2010, 35(8): 1751-1759.
[14]	BOMBACH E, ROVER I, MULLER A, et al. Technical Experience during Thermal Chemical Recycling of a 23 Year Old PV Generator Formerly Installed on Pellworm Island. 21st European Photovoltaic Solar Energy Conference, 2006: 2048-2053.
[15]	LIU QING, REN MING-SHU, LIU ZI-YING.Study and market of front-side silver paste for silicon solar cell.Information Recording Materials, 2012, 13(2): 39-46.
[16]	ZHANG LIFENG, CIFTJA ARIAN.Recycling of solar cell silicon scraps through filtration, Part I: Experimental investigation.Solar Energy Materials and Solar Cells, 2008, 92(11): 1450-1461.
[17]	MA LING-LING, QIN ZHI-HONG, ZHANG LU,et al. Peak fitting methods and parameter setting in XPS analysis for organic sulfur in coal. Journal of Fuel Chemistry Technology, 2014, 42(3): 277-283.
[18]	YIN ZONG-JIE, WANG TING, XING HUA-CHAO.Technique of data processing method during XPS analysis.Shandong Chemical Industry, 2017, 46(12): 89-93.
[19]	LIU FEN, ZHAO ZHI-JUAN, QIU LI-MEI,et al. Tables of peak positions for XPS photoelectron and auger electron peaks. Analysis and Testing Technology and Instruments, 2009, 15(1): 1-17.
[20]	TORU YAMASHITA, PETER HAYES.Analysis of XPS spectra of Fe2+ and Fe3+ ions in oxide materials.Applied Surface Science, 2008, 254(8): 2441-2449.