利用雷射刻劃技術改善非晶矽/單晶矽異質接面太陽能電池之光電特性研究

Improved Photovoltaic Characteristics of Amorphous-Si/Crystalline-Si Heterojunction Solar Cells Using Laser Scribing Technology

謝文烽(Wen-Feng Hsieh)

指導教授 ： 莊賦祥

共同指導教授 ： 鄭錦隆

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2010年)

摘要

本論文主要以超高頻電漿增強式化學氣相沉積系統(VHF- PECVD)研製異質接面太陽能電池。藉由調變氫氣稀釋比[SC %=SiH4/(SiH4+H2)×100 %]、氫氣鈍化、n-type Si摻雜濃度[Yn %= PH3/(SiH4+H2+PH3)×100 %]等實驗設計參數，分析薄膜之沉積速率、穿透率、電阻率、SEM參數等薄膜性質，進而探討薄膜對於異質接面太陽能電池元件特性之影響。實驗結果發現藉由調整薄膜沈積參數，即n-type a-Si之Yn%=0.05 %、厚度15 nm可使異質接面太陽能電池效率達5.28 %，開路電壓(Voc)= 0.51 V，短路電流(Jsc) =21.2 mA/cm2，填充因子(FF)=49.3 %。
利用雷射雕刻及濕蝕刻研製微奈米表面增加吸收照光的p-type Si/intrinsic Si/n-type Si (PIN)接面面積，提升異質接面矽晶太陽能電池光電特性為此論文另一重點，藉由雷射雕刻機直接在矽基片上，使用不同的雕刻參數，包含移動速度、功率、焦距及頻率等並配合濕式糙化製程有效增加PIN接面面積。實驗結果顯示，經由雷射雕刻及濕蝕刻後之表面其反射率在400-1000 nm量測範圍內其反射率皆低於10 %，且雷射加工點數越密集其反射率越低。而異質長接面設計元件之短路電流密度由19.4提升至22.9 mA/cm2，效率由3 %提升至3.6 %。

關鍵字

異質接面太陽能電池 ； 電漿增強式化學氣相沉積系統 ； 雷射刻劃

並列摘要

In this thesis, the improved photovoltaic characteristics of silicon heterojunction were investigated by mean of the very-high-frequency (VHF, 60 MHz) plasma-enhanced chemical vapour deposition (PECVD) under well-controlled discharge conditions. The modulated parameters, including the H2 plasma treatment, the silane concentration [SC %=[SiH4/(SiH4+H2)]×100 %], as well as doping concentration of n-type a-Si [Yn %= PH3/(SiH4+H2+PH3)×100 %] on the characteristics of the heterojunction solar cell were demonstrated. The deposition rates, the optical energy gaps (Eg), incident photon conversion efficiency (IPCE), scanning electron microscope (SEM), UV-VIS-IR spectroscopy and temperature dependent conductivity, respectively, Were studed, the results suggest that by modulating proper conditions, the heterojunction solar cells with a conversion efficiency of around 5.28 %, Jsc of 21.2 mA/cm2, Voc of 510 mV, and Fill factor (FF) of 49.2 % were demonstrated.

Improved photovoltaic characteristics of silicon heterojunction solar cells using micro- and nanostructured surface prepared by laser scribing and wet etching technology were demonstrated in this work. The modulated parameters include the velocity, power density, focus length, and frequency of the laser beam. The results indicate that the reflections of the nanostructured surface fabricated by laser scribing and wet etching technique were lower than 10 % for 400–1000 nm wavelength range. The design of hetero long- junction devices raise the short-circuit current density from 19.4 to 22.9 mA/cm2 and conversion effectivey from 3 % to 3.6%.

並列關鍵字

Heterojunction Solar Cell ； VHF-PECVD ； Laser Scribing

參考文獻

[1] W. Hoagland, “Solar energy”, Sci. Amer, Vol. 273, pp. 170-173, 1995.

[2] G. R. Davis, “Energy for plant earth”, Sci Amer, Vol. 263, no. 3, pp.21-27, 1990.

[3] K. N. Amulya and J. Goldemberg, “Energy for the developing world”, Sci Amer, vol. 263, no. 3, pp. 63-71, 1990.

[4] Martin A. Green, “Solar cell efficiency tables”, prog. Photovolt : Res. Appl., vol. 15, pp. 425–430, 2007.

[5] 林螢光, “光電子學-原理、元件與應用”, 全華出版社。