TY - JOUR
T1 - Electron transport mechanisms in Ag Schottky contacts fabricated on O-polar and nonpolar m-plane bulk ZnO
AU - Kim, Hogyoung
N1 - Publisher Copyright:
© 2015 KIEEME. All rights reserved.
PY - 2015/10
Y1 - 2015/10
N2 - We prepared silver Schottky contacts to O-polar and nonpolar m-plane bulk ZnO wafers. Then, by considering various transport models, we performed a comparative analysis of the current transport properties of Ag/bulk ZnO Schottky diodes, which were measured at 300, 200, and 100 K. The fitting of the forward bias current-voltage (I-V) characteristics revealed that the tunneling current is dominant as the transport component in both the samples. Compared to thermionic emission (TE), a stronger contribution of tunneling current was observed at low temperature. The reverse bias I-V characteristics were well fitted with the thermionic field emission (TFE) in both the samples. The presence of acceptor-like adsorbates, such as O2 and H2O, modulated the surface conductive state of ZnO, thereby affecting the tunneling effect. The degree of activation/passivation of acceptor-like adsorbates might be different in both the samples owing to their different surface morphologies and surface defects (e.g., oxygen vacancies).
AB - We prepared silver Schottky contacts to O-polar and nonpolar m-plane bulk ZnO wafers. Then, by considering various transport models, we performed a comparative analysis of the current transport properties of Ag/bulk ZnO Schottky diodes, which were measured at 300, 200, and 100 K. The fitting of the forward bias current-voltage (I-V) characteristics revealed that the tunneling current is dominant as the transport component in both the samples. Compared to thermionic emission (TE), a stronger contribution of tunneling current was observed at low temperature. The reverse bias I-V characteristics were well fitted with the thermionic field emission (TFE) in both the samples. The presence of acceptor-like adsorbates, such as O2 and H2O, modulated the surface conductive state of ZnO, thereby affecting the tunneling effect. The degree of activation/passivation of acceptor-like adsorbates might be different in both the samples owing to their different surface morphologies and surface defects (e.g., oxygen vacancies).
KW - Bulk ZnO
KW - Current transport
KW - Tunneling current
UR - http://www.scopus.com/inward/record.url?scp=84944748885&partnerID=8YFLogxK
U2 - 10.4313/TEEM.2015.16.5.285
DO - 10.4313/TEEM.2015.16.5.285
M3 - Article
AN - SCOPUS:84944748885
SN - 1229-7607
VL - 16
SP - 285
EP - 289
JO - Transactions on Electrical and Electronic Materials
JF - Transactions on Electrical and Electronic Materials
IS - 5
ER -