Sains Malaysiana 54(6)(2025): 1569-1582

http://doi.org/10.17576/jsm-2025-5406-12

 

Enhanced Solar Cell Efficiency via Reflectance on Silicon Wafers: Laser Texturing vs. Anisotropic Etching

(Kecekapan Sel Suria yang Dipertingkatkan melalui Pantulan pada Wafer Silikon: Tekstur Laser lwn. Goresan Anisotropik)

 

NURUL HUDA ABDUL RAZAK¹, BADARIAH BAIS^1,*, NOWSHAD AMIN², KAMARUZZAMAN SOPIAN³ & MD. AKHTARUZZAMAN⁴

 

¹Department of Electrical, Electronic and Systems Engineering, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia

²Department of Electrical and Electronic Engineering, Faculty of Engineering, American International University-Bangladesh (AIUB), 408/1 Kuratoli Road, Kuril, 1229 Dhaka, Bangladesh

³Department of Mechanical Engineering, Universiti Teknologi PETRONAS, 32610 Seri Iskandar, Perak, Malaysia

⁴Department of Chemistry, Faculty of Science, Islamic University of Madinah (IUM), 42351 Madinah, Saudi Arabia

 

Diserahkan: 19 Ogos 2024/Diterima:5 Mac 2025

 

Abstract

Due to its high refraction index, silicon (Si) reflects a significant amount of solar light of more than 37% of the sun’s spectral range, particularly when it does not strike the surface perpendicularly. This effect consequentially reduces solar cell efficiency due to electrical and optical losses. Surface texturing is essential for increasing the cells' photon-trapping and absorbing capabilities to improve the efficiency of low-performance solar cells. In this study, pulsed Nd:YAG lasers are used to texturize surfaces of silicon wafers. This procedure is quicker and easier and does not produce waste or pollutants. However, there are some disadvantages to laser texturing; one is that it may lower solar cell efficiency if the damaged layer caused by the laser texturing is not removed. In this study, the laser damage layer is washed off with potassium hydroxide (20%), also known as KOH. This paper also compares the reflectance of laser texturing and wet chemical etching on surfaces of crystalline silicon wafers.  The PerkinElmer Lambda 950 UV-VIS-NIR Spectrophotometer results indicate that laser texturing obtains a reflectance of 1% before and 9% after KOH treatment, in contrast to wet chemical etching, which has a reflectance of 16%. Laser texturing showed some efficiency, especially when texturing silicon wafer surfaces in parallel patterns, with a conversion efficiency of about 5% and grid patterns at 7.5%. This successful outcome demonstrates that laser texturing gives silicon solar cells a good alternative to traditional texturing techniques.

Keywords: Anisotropic etched; laser texturing; pulsed Nd:YAG laser; reflectance; silicon solar cells

 

Abstrak

Disebabkan indeks biasan yang tinggi, silikon (Si) memantulkan sejumlah besar cahaya matahari lebih daripada 37% daripada julat spektrum matahari, terutamanya apabila cahaya tidak mengenai permukaan secara tegak. Kesan ini secara tidak langsung mengurangkan kecekapan sel suria disebabkan oleh kerugian elektrik dan optik. Penteksturan permukaan adalah penting untuk meningkatkan keupayaan penyerapan dan perangkapan foton bagi meningkatkan kecekapan sel suria yang berprestasi rendah. Dalam kajian ini, laser Nd:YAG berdenyut digunakan untuk mentekstur permukaan wafer silikon. Prosedur ini lebih cepat dan mudah serta tidak menghasilkan sisa atau bahan pencemar. Walau bagaimanapun, terdapat beberapa kelemahan pada penteksturan laser; salah satunya adalah ia boleh mengurangkan kecekapan sel suria jika lapisan yang rosak akibat penteksturan laser tidak dibuang. Dalam kajian ini, lapisan kerosakan laser dibersihkan dengan kalium hidroksida (20%), yang juga dikenali sebagai KOH. Kertas ini juga membandingkan pantulan penteksturan laser dan pengukiran kimia basah pada permukaan wafer silikon kristal. Keputusan daripada Spektrofotometer PerkinElmer Lambda 950 UV-VIS-NIR menunjukkan bahawa penteksturan laser memperoleh pantulan sebanyak 1% sebelum dan 9% selepas rawatan KOH, berbanding dengan penteksturan kimia basah yang mempunyai pantulan sebanyak 16%. Penteksturan laser menunjukkan kecekapan tertentu, terutamanya apabila penteksturan permukaan wafer silikon dalam corak selari dengan kecekapan penukaran kira-kira 5% dan corak grid pada 7.5%. Hasil kejayaan ini menunjukkan bahawa penteksturan laser memberikan sel suria silikon alternatif yang baik kepada teknik penteksturan tradisional.

Kata kunci: Laser Nd:YAG berdenyut; pantulan; penteksturan anisotropik; penteksturan laser; sel suria silikon

 

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*Pengarang untuk surat-menyurat; email: badariah@ukm.edu.my