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可溶性半导体AAsSe2 (A = Li,Na) 具有直带间隙和强的第二波生成:一项结合实验和理论研究
Tarun K Bera1, Joon I Jang, Jung-Hwan Song
1Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
Journal of the American Chemical Society
|February 23, 2010
概括
新的金属石灰酸盐 (AAsSe2) 是极性半导体,具有可调节的带间隙. 玛-NaAsSe2表现出异常的非线性光学特性,使这些材料成为解决方案处理的有希望的材料.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 半导体物理 半导体物理
背景情况:
- 发现了一种新的三元金属石灰酸盐类,AAsSe2 (A = Li,Na).
- 这些化合物具有[AsQ2](-) 单元的无限单链,在上具有立体化学活性单一对.
- 结构多样性源于金属的影响,导致至少有四种不同的结构类型在Li(1-x) Na(x) AsSe2.2.
研究的目的:
- 描述AAsSe2材料的结构,电子和光学特性.
- 研究组成,结构和半导体特性之间的关系.
- 探索这些材料在非线性光学应用和解决方案处理方面的潜力.
主要方法:
- 单晶X射线衍射用于结构确定.
- 对分布函数 (PDF) 分析以揭示局部扭曲.
- 对电子属性的实验测量和理论频段结构计算 (sX-LDA FLAPW).
- 非线性光学 (NLO) 第二波生成 (SHG) 测量.
主要成果:
- 识别了四种结构类型 (α-LiAsSe2,β-LiAsSe2,gamma-NaAsSe2,delta-NaAsSe2),具有不同的链形状和包装.
- 观察了广泛的直接带间隙 (1.11 eV到2.23 eV),取决于组成.
- 玛-NaAsSe2表现出非常大的NLO第二波生成 (SHG) 响应 (337.9 pm/V),这是波段间隙> 1.0 eV的最高报告.
- AAsSe2 材料在常见溶剂中具有可溶性,方便溶液处理.
结论:
- AAsSe2化合物代表了一种新型的极性,直带间隙半导体,具有可调节的特性.
- 结构和电子性能受到金属类型和石化度的强烈影响.
- 由于其显著的SHG反应,Gamma-NaAsSe2是NLO应用的非常有前途的材料.
- 这些材料的溶解性为基于成本效益的解决方案的制造技术开辟了道路.
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