Detection and Characterization of Trap Levels in Semiconducting Ceramics

半导体陶瓷中陷阱能级的检测和表征

• 批准号: 05453077
• 负责人: TAKATA Masasuke
• 金额: $ 4.48万
• 依托单位: Nagaoka University of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05453077/
• 关键词: PTCR; ICTS; Barium Titanate; PMN; Grain Boundary; Electron Capture; HIP; Zinc Oxide; 酸化

The degradation phenomenon in a ZnO varistor was investigated by means of isothermal capacitance transient spectroscopy (ICTS), paying special attention to the trap levels. From the analysis of ICTS signals before and after degradation, the interface trap levels were found to shift toward the conduction band, and their energetical distribution was broadened. The degradation phenomenon was related to the interface states of the grain boundaries.The PTCR effect in BaTiO_3 is a grain boundary effect caused by a two dimensional layr of acceptor states which attract electrons from the grain interior. The acceptor state density and the energy gap, Es, between the conduction band and the energy level of the acceptor states govern the PTCR-properties. The samples annealed at high Po_2 (10 MPa) had a higher Es than the samples annealed at lower Po_2 (0.1 MPa), leading to improved PTCR-properties. Based on this finding and results from the literature, a phenomenological PTCR model and an accompanying PTCR chart for acceptor-donor-codoped BaTiO_3 were proposed. The PTCR chart clarifies that acceptor dopant concentrations, oxidation time, and oxygen partial pressure during oxidation or cooling can be optimized simultaneously to obtain the best PTCR ceramics.

通过等温电容瞬态光谱（ICT）研究了ZnO静脉曲张中的降解现象，特别注意陷阱水平。从降解前后的ICT信号的分析中，发现界面陷阱水平向传导带转移，并扩大了它们的能量分布。降解现象与晶界的界面状态有关。BATIO_3中的PTCR效应是由二维受体状态引起的晶界效应，这些受体状态吸引了晶粒内部的电子。受体状态密度和传导带和受体状态能量水平之间的能量间隙，ES控制PTCR-培训。在高PO_2（10 MPa）中退火的样品的ES比在较低的PO_2（0.1 MPa）处退火的样品高，从而改善了PTCR-Properties。根据文献的发现和结果，提出了一种现象学PTCR模型和伴随的受体补充batio_3的PTCR图。 PTCR图阐明了可以同时优化氧化或冷却过程中的受体掺杂剂浓度，氧化时间和氧部分压力，以获得最佳的PTCR陶瓷。

项目成果

M.Takata: "Relationship between Degradation Phenomenon and Trap Levels in a ZnO Varistor" Bull.Amer.Ceram.Soc.72. 96-98 (1993)

M.Takata：“ZnO 压敏电阻中的降解现象与陷阱水平之间的关系”Bull.Amer.Ceram.Soc.72。

B.Huybrechts et.al: "Proposed Phenomenological PTCR Model and Accompanying Phenomenological PTCR Chart" J.Am.Ceram.Soc.77. 286-88 (1994)

B.Huybrechts 等人：“提议的现象学 PTCR 模型和随附的现象学 PTCR 图”J.Am.Ceram.Soc.77。

B.Huybrechts, K.Ishizaki and M.Takata: ""Influence of High Oxygen Partial Pressure on the Positive Temperature Coefficient of Mn-doped Ba_<0.8>Sr_<0.2>TiO_3"" J.Eur.Ceram.Soc.11(5). 395-400 (1993)

B.Huybrechts、K.Ishizaki 和 M.Takata：“高氧分压对 Mn 掺杂 Ba_<0.8>Sr_<0.2>TiO_3 正温度系数的影响”J.Eur.Ceram.Soc.11(

Y.Watanabe,H.Endo,H.Semba and M.Takata: "Electronic Structure and Optical Non-linarity of Tin Oxide Thin Films" J.Non.Cryst.Solids. 178. 84-90 (1994)

Y.Watanabe、H.Endo、H.Semba 和 M.Takata：“氧化锡薄膜的电子结构和光学非线性”J.Non.Cryst.Solids。

T.Okamoto,B.Huybrechts and M.Takata: "Electric Field Sensitive Moving Hot Spot in GdBa_2Cu_3O_7-δ Ceramics" Jpn.J.Appl.Phys.33(9A). L1212-14 (1994)

T.Okamoto、B.Huybrechts 和 M.Takata：“GdBa_2Cu_3O_7-δ 陶瓷中的电场敏感移动热点”Jpn.J.Appl.Phys.33(9A) (1994)。