Effect of Schottky barrier height on hydrogen gas sensitivity of metal/TiO2 nanoplates

Abstract Anatase phase dominated TiO 2 nanoplates were deposited on p-Si by Radio-Frequency magnetron sputtering technique. Metal-TiO 2 nanoplates-Metal (M-TN-M) planer electrodes were fabricated using various metal electrodes such as Al, Ag, Ni, and Au. Temperature dependent current-voltage ( I-V ) characteristics of M-TN-M devices were measured in air and 1% hydrogen atmosphere. Barrier height between metal and TiO 2 nanoplates is decreased in presence of hydrogen as compared to air and increases with temperature. The sensing response of the device is strongly dependent on the alteration of barrier height and operating temperature. The relative response was observed ∼46% for Ohmic Al electrodes. The effective barrier heights were measured to be ∼0.15 eV for Ag, ∼0.17 eV for Ni and ∼0.19 eV for Au electrodes at 175 °C and corresponding change in relative response were measured ∼49%, ∼58%, and ∼77%, respectively. Response and recovery times for highest sensitivity device (Au-TN-Au) were found to be ∼7 and 114 s respectively at 175 °C operating temperature.

[1]  S. Rahbarpour,et al.  Diode type Ag–TiO2 hydrogen sensors , 2013 .

[2]  Ion Tiginyanu,et al.  Selective hydrogen gas nanosensor using individual ZnO nanowire with fast response at room temperature , 2010 .

[3]  W. Wlodarski,et al.  Anodized nanoporous WO3 Schottky contact structure for hydrogen and ethanol sensing , 2015 .

[4]  K. Cheong,et al.  Advances of SiC-based MOS capacitor hydrogen sensors for harsh environment applications , 2010 .

[5]  K. Zakrzewska,et al.  TiO2-Based Nanomaterials for Gas Sensing—Influence of Anatase and Rutile Contributions , 2017, Nanoscale Research Letters.

[6]  A. Berg,et al.  Ammonia sensors and their applications - a review , 2005 .

[7]  Oleg Lupan,et al.  ighly sensitive and selective hydrogen single-nanowire nanosensor , 2012 .

[8]  Amit Kumar,et al.  A Low-Energy Room-Temperature Hydrogen Nanosensor: Utilizing the Schottky Barriers at the Electrode/Sensing-Material Interfaces , 2010, IEEE Electron Device Letters.

[9]  P. Gouma,et al.  ANATASE-TO-RUTILE TRANSFORMATION IN TITANIA POWDERS , 2001 .

[10]  Makoto Egashira,et al.  Hydrogen-sensing properties of anodically oxidized TiO2 film sensors: Effects of preparation and pretreatment conditions , 2005 .

[11]  Makoto Egashira,et al.  Preparation of porous tin dioxide powder by ultrasonic spray pyrolysis and their application to sensor materials , 2008 .

[12]  Chengchao Li,et al.  Surface-depletion controlled gas sensing of ZnO nanorods grown at room temperature , 2007 .

[13]  F. Hossein-Babaei,et al.  Separate assessment of chemoresistivity and Schottky-type gas sensitivity in M–metal oxide–M′ structures , 2011 .

[14]  Yun-han Ling,et al.  Reverse bias voltage dependent hydrogen sensing properties on Au–TiO2 nanotubes Schottky barrier diodes , 2016 .

[15]  Lianmao Peng,et al.  Floating growth of large-scale freestanding TiO2 nanorod films at the gas-liquid interface for additive-free Li-ion battery applications. , 2014, ACS applied materials & interfaces.

[16]  G. Korotcenkov.  The role of morphology and crystallographic structure of metal oxides in response of conductometric-type gas sensors , 2008 .

[17]  Eric Borguet,et al.  TiO(2)/LiCl-based nanostructured thin film for humidity sensor applications. , 2011, ACS applied materials & interfaces.

[18]  K. Kalantar-zadeh,et al.  Nanoporous Nb2O5 hydrogen gas sensor , 2013 .

[19]  T. Roch,et al.  Hydrogen gas sensors based on nanocrystalline TiO2 thin films , 2011 .

[20]  A. Rakhshani,et al.  Charge transport mechanisms in Au-CdTe space-charge-limited Schottky diodes , 1998 .

[21]  M. Ghantasala,et al.  Characterization and testing of Pt/TiO2/SiC thin film layered structure for gas sensing , 2013 .

[22]  S. Shah,et al.  Effect of cobalt doping on the phase transformation of TiO2 nanoparticles. , 2005, Journal of nanoscience and nanotechnology.

[23]  Mahesh Kumar,et al.  Schottky-contacted vertically self-aligned ZnO nanorods for hydrogen gas nanosensor applications , 2015 .

[24]  Sheikh A. Akbar,et al.  Gas Sensors Based on One Dimensional Nanostructured Metal-Oxides: A Review , 2012, Sensors.

[25]  M. Wu,et al.  Effect of noble metal catalyst on titania exhaust gas oxygen sensor , 1993 .

[26]  Daqiang Zhang,et al.  A Survey on Gas Sensing Technology , 2012, Sensors.

[27]  Mahesh Kumar,et al.  Temperature dependent electrical transport studies of self-aligned ZnO nanorods/Si heterostructures deposited by sputtering , 2014 .

[28]  Wojtek Wlodarski,et al.  A comparison of forward and reverse bias operation in a Pt/nanostructured ZnO Schottky diode based hydrogen sensor , 2009 .

[29]  Katsuhiko Ariga,et al.  A Special Section on Nanocomposites and Nanoporous Materials , 2010 .

[30]  M. Kompitsas,et al.  Low–Temperature Hydrogen Sensors Based on Au Nanoclusters and Schottky Contacts on ZnO Films Deposited by Pulsed Laser Deposition on Si and ${\hbox{SiO}}_{2}$ Substrates , 2007, IEEE Sensors Journal.

[31]  Jinghua Wu,et al.  Scalable synthesis of TiO2/graphene nanostructured composite with high-rate performance for lithium ion batteries. , 2012, ACS nano.

[32]  Zhifu Liu,et al.  Hydrogen sensing properties of Pd-doped SnO2 sputtered films with columnar nanostructures , 2009 .