摘要On the basis of the Schottky barrier and thermionic emission models, the temperature dependence of barrier height in ZnO varistors is investigated by the I-V characteristics in a wide temperature range from 93K to 373K. The obtained barrier height decreases with reducing temperature, which is ascribed to the contribution of tunneling current in measured current. From the proposed equivalent circuit, it is suggested that two current components coexist. One is thermionic emission current, which reflects the thermionic emission barrier height. The other is tunneling current, which appears even at low voltage, especially in low temperature ranges, and thus makes the barrier height obtained from measured current vary with temperature.
Abstract：On the basis of the Schottky barrier and thermionic emission models, the temperature dependence of barrier height in ZnO varistors is investigated by the I-V characteristics in a wide temperature range from 93K to 373K. The obtained barrier height decreases with reducing temperature, which is ascribed to the contribution of tunneling current in measured current. From the proposed equivalent circuit, it is suggested that two current components coexist. One is thermionic emission current, which reflects the thermionic emission barrier height. The other is tunneling current, which appears even at low voltage, especially in low temperature ranges, and thus makes the barrier height obtained from measured current vary with temperature.
LI Sheng-Tao;YANG Yan;ZHANG Le;CHENG Peng-Fei;LI Jian-Ying. Effect of Tunneling Current on Schottky Barrier Height in ZnO Varistors at Low Temperature[J]. 中国物理快报, 2009, 26(7): 77201-077201.
LI Sheng-Tao, YANG Yan, ZHANG Le, CHENG Peng-Fei, LI Jian-Ying. Effect of Tunneling Current on Schottky Barrier Height in ZnO Varistors at Low Temperature. Chin. Phys. Lett., 2009, 26(7): 77201-077201.
[1] Tung R T 1991 Appl. Phys. Lett. 58 2821 [2] Edmund D and Jozef O 1994 Appl. Phys. Lett. 65575 [3] Subhash C and Jitendra K 1997 J. Appl. Phys. 82 5005 [4] Subhash C and Jitendra K 1996 J. Appl. Phys. 80 288 [5] Bandyopadhyay S, Bhattacharyya A and Sen S K 1999 J.Appl. Phys. 85 3671 [6] Dmitruk N L et al 2002 Appl. Surf. Sci. 190455 [7] Gumus A, Turut A, and Yalcin N 2002 J. Appl. Phys. 91 245 [8] Acar S, Karadeniz S, Tugluoglu N, Selcuk A B and Kasap M2004 Appl. Surf. Sci. 233 373 [9] Rodrigues A M 2008 J. Appl. Phys. 103 083708 [10] Kaiser W J and Bell L D 1988 Phys. Rev. Lett. 60 1406 [11] Sullivan G P, Tung R T, Pinto M R and Graham W R 1991 J. Appl. Phys. 70 7403 [12] Alim M A, Li S T, Liu F Y and Cheng P F 2006 Phys.Status Solidi A 203 410 [13] Pike G E 1984 Phys. Rev. B 30 795 [14] Clark D C 1969 J. Am. Ceram. Soc. 52 485 [15] Calvet M L E, Wheeler R G and Reed M A 2002 Appl.Phys. Lett. 80 1761 [16] Cheung S K and Cheung N W 1986 Appl. Phys. Lett. 49 85 [17] Mahan G D, Levinson L M and Philipp H R 1979 J.Appl. Phys. 50 2799 [18] Ohdomari I, Kuan T S and Tu K N 1979 J. Appl. Phys. 50 7020 [19] Philipp H R and Levinson1 L M 1976 J. Appl. Phys. 47 3177
2009, Vol. 26 
