[19p-131-1~15] 15.7 結晶評価，不純物・結晶欠陥

[19p-131-7] Σ3{111}対称傾角粒界の不純物偏析能とキャリア再結合速度に対する傾角のずれの影響

〇大野 裕¹、沓掛 健太朗¹、玉岡 武泰²、竹田 精治²、清水 康雄³、海老澤 直樹³、井上 耕治³、永井 康介³、宇佐美 徳隆⁴ (1.東北大金研、2.阪大産研、3.東北大金研大洗セ、4.名大工)

キーワード：非対称粒界、シリコン太陽電池

We discuss the recombination activity of asymmetric Σ3{111} GBs with the <110> tilt axis, whose GB planes are slightly inclined from {111}. Even though the activity is negligible for the symmetric Σ3{111} GBs of which the GB plane is just on {111}, the activity is high for the asymmetricΣ3{111} GBs even when their inclination angle is small. Most segments of the asymmetric GBs are composed of arrays of GB dislocations lying on symmetric Σ3{111} GBs. Those dislocations are edge-type with the Burgers vector of 1/3<111>. Atom probe tomography reveals that oxygen atoms would segregate at the atomic sites under tensile stress above about 2 GPa, which are introduced along the GB plane due to the GB dislocations. Carbon atoms also segregate, while they would locate only nearby the dislocation cores. The correlation between the recombination activity and the segregation ability of impurity atoms will be discussed.