多層類鑽碳膜之製造及其在抗反射披覆之應用

Fabrication of multilayer DLC films and their applications for antireflection Coating

張志文(Chin-Wen Chang)

指導教授 ： 林啟瑞

國立臺北科技大學/機電學院/製造科技研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00278

摘要

目前商業化太陽能電池中，結晶矽約佔90﹪以上。由於矽晶系的太陽能電池具有很高的反射係數，為了減少太陽光自表面反射損失的機率，進而提高電池的效率。本論文之研究利用RF磁控濺鍍法，在矽晶圓（100）上披覆多層類鑽碳(DLC)膜，利用其具備接近天然鑽石的性質，並隨著膜內sp2所佔比例不同可控制折射率之變化，應用於抗反射層的製作，以有效降低反射的損失。
本研究之結果主要分為DLC膜的結構特性、潤濕性及光學特性分析等三部份作為探討。由分析結果可得知矽晶圓在鍍上DLC膜後的平均粗糙度(Ra)值皆在1 nm以下，使其對光散射影響可有效減少。同時，對於DLC膜的潤濕性分析，我們得到隨著sp2比例的降低，具有較好的疏水性，且最佳的接觸角為94°，相較未鍍膜其接觸角為46°之下提升了104﹪。最後，利用不同折射率製程參數，配合光學膜層堆疊設計鍍製高低折射率之多層DLC膜，由光譜儀分析得知光反射率在可見光中心波長(550 nm)位置相較於單層膜為低，且同時在全波長範圍內之光反射率也較單層膜有所下降。

關鍵字

類鑽碳膜 ； 抗反射 ； 疏水性 ； 太陽能電池

並列摘要

Diamond-like carbon (DLC) films are current applied in several important fields of optics, electricity, and solid state devices, etc., due to their excellent properties such as high hardness, high electrical resistivity, and transparency to visible light and chemical inertness. As DLC films have wide bandgaps and adjustable refractive index, they can be utilized as protective coatings for anti-reflective (AR) coatings for solar cells. In this study, DLC films were deposited on silicon (100) substrate by the unbalance magnetron sputtering method for silicon solar cell applications. In order to improve the reflection coefficient of solar cell, these AR coatings were multi-layer structure comprising single-layers DLC films which have different refractive index. The synthesized films were characterized with scanning electron microscopy (SEM), atomic forced microscopy (AFM), Raman spectra, and UV/VIS spectrophotometer. From Raman spectra and UV/VIS measurements, as G-peak position shifts to the high Raman shift side, a lower percentage of sp2 bonds and high refractive index are obtained. Hydrophobicity in these films was studied by measuring the contact angles of DI water droplets and it was found that the films were extremely hydrophobic as the best contact angle was 94° while it was 46° of uncoated film. From AFM results, average roughness of the as-grown films are less than 1 nm and it was found that these films had extremely smooth surface, very high uniformity, and efficiency of space filling over large areas. Moreover, from UV/VIS spectrometry, the prepared multi-layer DLC films possess a lower reflection coefficient than that of single-layer ones on the whole wavelength range. It opens realistic perspective for the preparation of high performance anti-reflection coating for research and development purposes.

並列關鍵字

diamond-like carbon ； antireflection ； hydrophobicity ； solar cell

參考文獻

國立中央大學光電科學研究所，桃園，2006。

“Diamond like carbon used as antireflective coating on crystalline silicon solar

cells,” Diamond & Related Materials, Vol. 18, 2009, pp. 1028-1030.

[4] 吳永企，射頻離子束濺鍍(TiO2)x(Ta2O5)1-x混合膜之特性，碩士論文，

[6] J.C. Angus and C.C. Hayman, “Low-pressure,metastable growth of diamond