Impurity Compensation Effect Induced by Tin Valence Change in α-Ga1.4Sn0.6O3 Thin Films

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• 作者：Xiaolong ZhaoZhenping Wu ; Wei Cui ; Yusong Zhi ; Daoyou Guo ; Linghong Li ; Weihua Tang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2017
• 出版时间：January 11, 2017
• 年：2017
• 卷：9
• 期：1
• 页码：983-988
• 全文大小：495K
• ISSN：1944-8252

文摘

Corundum-structured α-phase Ga_1.4Sn_0.6O₃ thin films have been deposited on m-plane Al₂O₃(300) substrates using laser molecular beam epitaxy technology. With increasing of the oxygen partial pressure, the crystal lattice of Ga_1.4Sn_0.6O₃ films expands due to tin ions valence changes from Sn⁴⁺ to Sn²⁺. The resistivity of the film deposited under 3 × 10^–5 Pa is 3.54 × 10⁴ Ω·cm, which decreases by about 2 orders of magnitude than that fabricated under 3 × 10^–1 Pa. The mixture valence of Sn²⁺ and Sn⁴⁺ ions leads to the impurity altitude compensation effect. The deep ultraviolet photodetector based on α-phase Ga_1.4Sn_0.6O₃ thin films was fabricated. With the oxygen partial pressure reducing gradually, the dark current and the photocurrent increase, and the relaxation time constants diminish, respectively.