銅銦鎵硒薄膜太陽電池鉬背電極層之製備與特性分析

Preparation and Characterization of Mo Films Used as the Back Contact of CIGS Thin-film Solar Cells

劉永健(Yong-Jian Liu)

指導教授 ： 呂宗昕

國立臺灣大學/工學院/化學工程學研究所/碩士(2014年)

https://doi.org/10.6342/NTU.2014.10264

摘要

本研究探討鉬型態於硒化反應中的影響。鉬膜透過直流濺鍍法製備在玻璃基板上，透過濺鍍參數控制鉬型態，接著在硒氣氛下於管爐中進行硒化反應。探討硒化鉬生成機制以及鉬型態對於硒化鉬生成的影響。
在本研究中，三角錐狀的鉬膜透過直流濺鍍法被製備，粒徑隨瓦數由100 W增加至250 W而從10 nm增加至50 nm。在硒化製程中，發現硒化鉬可以在400oC下被製備，隨著硒化鉬生成，表面型態從原來的三角錐狀變成圓角狀，藉由GIXD的分析，可以發現硒化鉬從鉬膜表面開始形成，並且在硒化後，薄膜底下仍含有未反應的鉬。隨著製備鉬的瓦數增加，生成的硒化鉬厚度從0.26 μm下降至0.05 μm。四點探針量測電阻結果顯示，硒化後薄膜片電阻均提升，然而隨著製備鉬的瓦數增加，硒化後薄膜片電阻增加量從4.88下降至0.25 Ω/cm2。鉬生成硒化鉬的轉化效率亦隨製備鉬瓦數增加從13.4 %降至6.9 %。經由此研究證實，藉由濺鍍瓦數的增加使鉬膜晶粒尺寸顯著提升，進而有效抑制硒化鉬的生成。因此仍保留鉬層的良好電性。

關鍵字

銅銦鎵硒太陽電池 ； 鉬背電極 ； 硒化鉬 ； 硒化製程 ； 濺鍍製程

並列摘要

In this work, the effects of Mo films prepared at different sputtering conditions on the formation of MoSe2 during selenization were investigated. Mo films were prepared via the DC magnetron sputtering process. Then, the prepared Mo films were selenized under different condition in the horizontal tube furnace. The microstructures of Mo films were dependent on the sputtering parameters. With increasing the sputtering powers ranging from 100 W to 250 W, the grain size of Mo films was increased from 10 nm to 50 nm.
The formation of MoSe2 was observed after Mo films were selenized at 400oC. With the existence of MoSe2, the surface microstructures of the selenized Mo films were changed from the initial pyramidal-like grains into rounded-like grains. On the other hand, the sheet resistance of the selenized Mo films was increased with increasing the selenization temperature since large amount of MoSe2 was formed at high temperature.
For investigating the effects of Mo films with different microstructures on the reactivity of Mo films with selenium vapor, Mo films prepared at sputtering powers ranging from 100 W to 250 W were selenized at the same condition. Based on the GIXD analysis, after the selenization process of Mo films prepared at the sputtering power of 100 W, the region from the surface to the depth of 0.26 μm was all MoSe2. As the sputtering power was increased from 150 W to 250 W, the thickness of MoSe2 layer was decreased from 0.13 μm to 0.05μm and the increase in the sheet resistance of the selenized Mo films was also significantly decreased. The conversion ratio of MoSe2 calculated from the increase in the film thickness was significantly reduced with increasing the sputtering power. It is indicated that Mo films prepared at high sputtering power exhibit the low reactivity with the selenium vapor due to the relatively large grain size, thereby effectively suppressing the formation of MoSe2. In this way, Mo films with high conductivity were remained after the selenization process and the performance of CIGS can be improved.

並列關鍵字

CIGS thin-film solar cell ； Mo back contact ； Molybdenum diselenide ； selenization process ； sputtering process

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