Modified heterojunction based on zinc oxide thin film for hydrogen gas-sensor application

✍ Scribed by S. Basu; A. Dutta

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 473 KB
• Volume: 22
• Category: Article
• ISSN: 0925-4005
• DOI: 10.1016/0925-4005(94)87004-7

✦ Synopsis

Device-quahty ZnO thm film IS deposlted by usmg an mdlgenously developed moddied CVD method and a Pd/ZnO/p-B heteropmctlon IS fabricated A study of the current-voltage characterlstlcs of the heterolunctlon m pure air and m air with different concentrations (2000-20 000 ppm) of hydrogen reveals that the device can be used as a room-temperature hydrogen sensor down to a level of hydrogen below Its explosron mucture mth an The saturatwn sensltlvlty and time response of the device wth respect to the dtierent hydrogen concentrattons m air has been studled The device operatmg at 1 V forward bias shows a maxLmum saturation sensltlvlty m different hydrogen concentrations At 20 000 ppm Hz m air, the sensltlvlty 1s found to be 5 x 102, while the time response IS 162 s The mcrease of surface ConductMly of ZnO at the Pd/ZnO Interface due to the adsorption and chemical mteractlon of hydrogen 1s found to play a key role m sensmg This mechamsm of hydrogen sensing 1s verdied by a double-metal-gate heterolunctlon