Title :
Hydrogen Sensing Characteristics of Porous Pd/SiO2/GaN Schottky Diode
Author :
Chen, Yu-Jen ; Chou, Yen-I ; Wu, Chung-Yeh ; Lin, Shih-Da ; Huang, Yu-Wei ; Chen, Huey-Ing
Author_Institution :
Nat. Cheng Kung Univ., Tainan
Abstract :
In this work, the porous Pd/SiO2/GaN Schottky diode was fabricated by thermal evaporation (TE) for hydrogen sensing. The current-voltage (I-V) characteristics of the studied device were measured under hydrogen concentrations of 15 - 9970 ppm H2/air and temperatures of 303 - 515 K. Furthermore, the hydrogen sensing performances of this device were investigated via the steady-state and transient detections. From experimental results, the studied device demonstrated excellent sensing performances with low detection limit (about ppb level), wide detection range (15 -9970 ppm), high sensitivity, and fast response and recovery rates (within several seconds for detection of 9970 ppm H2/air). For the detection of 15 ppm at 423 K, the relative sensitivity even reached to 490%. In addition, the relative sensitivity was increased as either the hydrogen concentration or the detection temperature was incresaed. As compared with the dense structured device, the porous structured Pd/ SiO2/GaN Schottky diode exhibited more superior sensing characteristics, especially at low hydrogen concentration with a relatively high sensitivity.
Keywords :
Schottky diodes; chemical sensors; current-voltage characteristics; hydrogen concentration; hydrogen sensing characteristics; porous Schottky diode; relative sensitivity; thermal evaporation; transient detection; Atomic layer deposition; Chemical vapor deposition; Gallium nitride; Hydrogen; Insulation; Schottky barriers; Schottky diodes; Surface morphology; Tellurium; Temperature sensors;
Conference_Titel :
Electron Devices and Solid-State Circuits, 2007. EDSSC 2007. IEEE Conference on
Conference_Location :
Tainan
Print_ISBN :
978-1-4244-0637-1
Electronic_ISBN :
978-1-4244-0637-1
DOI :
10.1109/EDSSC.2007.4450245