IV族半導體基板鈍化層研究

Research on the Passivation of IV Group Semiconductor Substrates

黃鼎育(Ding-yu Huang)

指導教授 ： 陳昇暉

國立中央大學/理學院/光電科學與工程學系/碩士(2014年)

摘要

本研究可以分為兩個部份來討論，其一是矽基板與鍺基板上鈍化層的分析，第二是比較分析兩種不同基板上鈍化效果。利用沉積四種不同鈍化層薄膜，分別是SiO2/SiNx、Ta2O5、TiO2、Al2O3，鍍製在IV族基板上，期望藉此改善太陽能電池基板的載子表面復合。鈍化層的分析主要分成電性分析以及薄膜成分的分析，觀察對不同鈍化薄膜於不同基板鈍化效果。在電性分析上量測少數過量載子生命週期值與電流電壓特性曲線，在成份分析上量測X-ray光電子能譜儀。
根據本實驗的分析結果，在矽基板上SiO2/SiNx堆疊結構有最好的鈍化效果，少數過量載子生命週期值為127.97 μs，樣品漏電流為5.8×10-8 A(0.5V)，是四種鈍化層中表現最佳。而在鍺基板上則是Ta2O5薄膜具有最好的鈍化效果，少數過量載子生命週期值為9.41μs，樣品漏電流值為9.77×10-5 A(0.5V)，亦是四種鈍化材料中表現最佳。

關鍵字

鈍化 ； 五氧化二鉭 ； 氮化矽 ； 三氧化二鋁 ； 二氧化鈦 ； 載子生命週期 ； 電性分析

並列摘要

There are two main parts in this research. One is the analysis of the passivation layers on the silicon substrates or germanium substrates. Another one is the compare of the passivation effect on the different substrates (crystalline silicon and germanium). Four different materials were used to be the passivation layers of the group IV semiconductor substrates to reduce the recombination of the substrate surface. They are SiO2/SiNx, Ta2O5, TiO2 and Al2O3, the electrical and stoichiometric properties of the passivation layers are including their leakage current, excess minority carrier lifetime and atomc content ratio on the group IV semiconductor substrates.
According to the experimental results, the SiO2/SiNx layers on the silicon substrate, achieved the best passivation effect. The minority lifetime is 127.97 μs, and the leakage current is 5.8×10-8 A (0.5 V). And the Ta2O5 layer on the germanium substrates also achieved the best passivation effect. The minority lifetime is 9.41μs and the leakage current is 9.77×10-5 A (0.5 V).

並列關鍵字

passivation ； Ta2O5 ； SiNx ； Al2O3 ； TiO2 ； carrier lifetime ； electric properties analysis

參考文獻

[1.3] P. Würfel, Physics of Solar Cells, Willy -VCH Verlag GmbH & Co. KgaA, 2005.

[1.4] Gavin Conibeer, “Review: Third-generation photovoltaics”, Material Today, 10 (11), pp. 745-747, 1987.

[1.6] A.Luque and A.Martí, " Increasing the efficiency of ideal solar cells by photon induced transitions at intermediate levels", Physical Review Letters, 78 (26), pp.5014-5017, Feb 1997.

[2.1] C. Leguijt, et al., “Very low surface recombination velocities on 2.5 Ω cm Si wafers, obtained with low-temperature PECVD of Si-oxide and Si-nitride”, Solar Energy Materials and Solar Cells, 34 (1-4), pp. 177-181, 1994.

[2.2] M. Kerr, et al., “Comparison of the open circuit voltage of simplified PERC cells passivated with PECVD silicon nitride and thermal silicon oxide”, Progress in Photovoltaics: Research and Applicaions , 8 (5), pp. 529-536, 2000.