Observation of an electrical breakdown at ZnO Schottky contacts in varistors

被引：10

作者：

Kaufmann, Benjamin ^{[1
]}

Billovits, Thomas ^{[1
,2
]}

Supancic, Peter ^{[1
,2
]}

机构：

[1] Montanuniversitat, Dept Mat Sci, Chair Struct & Funct Ceram, Franz Josef Str 18, A-8700 Leoben, Austria

[2] Mat Ctr Leoben Forsch GmbH, Roseggerstr 12, A-8700 Leoben, Austria

来源：

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY | 2021年 / 41卷 / 03期

关键词：

ZnO varistors; Schottky barrier; Electrical breakdown; I-V characteristics; Micro 4-point probe method; GRAIN-BOUNDARIES; TRANSPORT;

D O I：

10.1016/j.jeurceramsoc.2020.10.052

中图分类号：

TQ174 [陶瓷工业]; TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

We report an electrical breakdown (EBD) at metal/ZnO junctions in varistors with Ag-Pd and Pd electrodes. It was found that these junctions show Schottky behaviour with a mean Schottky barrier height (SBH) of 0.70 +/- 0.07 eV for Bi-based varistors with Ag-Pd (80-20 %) electrodes and a mean SBH of 0.47 +/- 0.03 eV for Pr-based varistors with Pd electrodes. All investigated electrode-to-grain junctions (EGJ) exhibited an EBD of the Schottky barrier in the reverse current direction, whereas the mean EBD voltage for the Bi-based varistors is 3.5 V and 2.5 V for the Pr-based varistors. Observation of electroluminescent light at the EGJ interface clearly indicates that the EBD is related to electron-hole generation, similar to the EBD at the grain boundaries in the ZnO microstructure. This shows that a similar good but asymmetric varistor effect, as it is observed at grain boundaries, can be observed at EGJ.

引用

页码：1969 / 1974

页数：6

共 24 条

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