Takashi Fuyuki, Hayato Kondo, Yasue Kaji, Tsutomu Yamazaki, Yu Takahashi, Yukiharu Uraoka

Graduate School of Materials Science, Nara Institute of Science and Technology

8916-5 Takayama, Ikoma, Nara 630-0192 Japan

Takashi Fuyuki, Hayato Kondo, Yasue Kaji, Tsutomu Yamazaki, Yu Takahashi, Yukiharu

ONE SHOT MAPPING OF MINORITY CARRIER DIFFUSION LENGTH

IN POLYCRYSTALLINE SILICON SOLAR CELLS USING ELECTROLUMINESCENCE

學號： MA310107報告者：陳威昇指導老師：林克默

摘要簡介實驗

排放和討論分析結論參考

目錄

摘要• The novel technique of analyzing the spatial distribution of

minority carrier diffusion length was investigated in detail by utilizing the photographic surveying of electroluminescence emitted from polycrystalline Si cells. The emitted infrared light (peak wavelength: 1150 nm) from a sample cell under the forward bias was captured by a cooled CCD camera. The intensity was found to be proportional to the minority carrier diffusion length regardless of the running current density, which gave the quantitative information of the minority carrier diffusion length distribution with high reliability. The deteriorated areas andlor aggregation of defects were detected by a simple one-shot capturing of the emitted light.

簡介• Crystalline silicon (Si) solar cells dominate the worldwide

share of photovoltaic systems utilizing the advantages of stable performance with high efficiency. Polycrystalline Si (poly-Si) cells using cast substrates have been developed for long years due to the capability of mass production with low cost. The improvement of conversion efficiency is strongly required to fulfill the demand of practical nstallation. The accurate and quick characterization of material properties is the key issue to develop the high performance cetls. and especially, the evaluation of the minority carrier diffusion length (or lifetime) is essential since it governs the collection efficiency in the cell.

實驗

排放和討論分析

結論• The novel technique of analyzing the spatial distribution of

the minority carrier diffusion length by the photographic surveying method was examined in detail. Under the 'forward bias condition, the cell emits infrared light. The emission intensity has the one to one relation with the minority carrier diffusion length, which yields the quantitative information of the minority carrier diffusion length distribution. The emission intensity had a super-linear dependence upon the running forward current. The applicability of proposed technique was discussed.

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Solar Cells, 36, 169 (1 995).

• [2] 0.Porre. M-Stemmer and M.Pasquinelli; Materials Science and Engineering B. 24, 188 (1994).

• [3] MSakitani, K.Nishioka, T.Yagi, YYamamoto,

• Y.lshikawa, Y.Uraoka and T.Fuyuki,

• Solid State Phenomena, 93, 351 (2003).

• [4] W. Seifert, M.Kittler and J.Vanhellemont; Materials Science and Engineering B, 42, 260 (1 996).

• [5] T.Fuyuki. H.Kondo, T.Yamazaki. and Y.Takahashi; Applied Physics Letters (submitted).