TY - JOUR
T1 - Nanocontact Disorder in InP Nanowire Devices for the Enhancement of Visible Light and Oxygen Gas Sensitivities
AU - Lin, Yen Fu
AU - Chang, Chia Hung
AU - Hung, Tsu Chang
AU - Liu, Zhaoping
AU - Fang, Jiye
AU - Jian, Wen-Bin
PY - 2017/1/1
Y1 - 2017/1/1
N2 -
InP nanowires, synthesized through a self-seeded growth approach, are used in the fabrication of field-effect transistors which consist of source, drain, and back-gate electrodes. The weak gating voltage dependence implies low carrier concentrations whereas its behavior reveals native n-type doping in InP nanowires. These InP nanowire devices exhibit a vast variation of room-temperature resistance that raises a question about contact resistance. For devices of low room-temperature resistance, electron transport in InP nanowires is investigated using temperature dependent resistance in the temperature range between 80 and 300 K, and it can be analyzed using the model of thermal activation. For other devices of high room-temperature resistance, we take into account nanocontact resistance. Models of both Schottky contact and Mott's variable range hopping (VRH) are considered. The two resistances are connected in parallel to give total contact resistance of InP nanowire devices. After fitting experimental data by the proposed model, we estimate effective Schottky barriers and disorder contributions to nanocontact resistance. The effective Schottky barrier, and the nanocontact Schottky and Mott's VRH resistances are plotted as a function of the device room-temperature resistance which indicates the scale of disorder. Using room-temperature resistance of InP nanowire devices, the devices are classified into nanowire- or contact-dominated devices. The two different class of devices are used to check their photo- and gas-sensitivities. The contact-dominated InP nanowire devices show low dark current and low photocurrent as usual, but these contact-dominated devices give high ratio of photo- to dark-current. That result reveals a high photo-sensitivity for those devices of high nanocontact resistance. On the other hand, for gas sensing experiments, the contact-dominated devices show as well a high ratio of resistance under O
2
to that under N
2
gas exposure.
AB -
InP nanowires, synthesized through a self-seeded growth approach, are used in the fabrication of field-effect transistors which consist of source, drain, and back-gate electrodes. The weak gating voltage dependence implies low carrier concentrations whereas its behavior reveals native n-type doping in InP nanowires. These InP nanowire devices exhibit a vast variation of room-temperature resistance that raises a question about contact resistance. For devices of low room-temperature resistance, electron transport in InP nanowires is investigated using temperature dependent resistance in the temperature range between 80 and 300 K, and it can be analyzed using the model of thermal activation. For other devices of high room-temperature resistance, we take into account nanocontact resistance. Models of both Schottky contact and Mott's variable range hopping (VRH) are considered. The two resistances are connected in parallel to give total contact resistance of InP nanowire devices. After fitting experimental data by the proposed model, we estimate effective Schottky barriers and disorder contributions to nanocontact resistance. The effective Schottky barrier, and the nanocontact Schottky and Mott's VRH resistances are plotted as a function of the device room-temperature resistance which indicates the scale of disorder. Using room-temperature resistance of InP nanowire devices, the devices are classified into nanowire- or contact-dominated devices. The two different class of devices are used to check their photo- and gas-sensitivities. The contact-dominated InP nanowire devices show low dark current and low photocurrent as usual, but these contact-dominated devices give high ratio of photo- to dark-current. That result reveals a high photo-sensitivity for those devices of high nanocontact resistance. On the other hand, for gas sensing experiments, the contact-dominated devices show as well a high ratio of resistance under O
2
to that under N
2
gas exposure.
KW - InP nanowire
KW - disorder
KW - nanocontact
KW - nanowire electronics
UR - http://www.scopus.com/inward/record.url?scp=85029746100&partnerID=8YFLogxK
U2 - 10.1016/j.piutam.2017.03.034
DO - 10.1016/j.piutam.2017.03.034
M3 - Conference article
AN - SCOPUS:85029746100
SN - 2210-9838
VL - 21
SP - 33
EP - 39
JO - Procedia IUTAM
JF - Procedia IUTAM
T2 - Symposium on Nanoscale Physical Mechanics, IUTAM 2016
Y2 - 23 May 2012 through 27 May 2012
ER -