An n-$\hbox{SnO}_{x}$ /i-Diamond/p-Diamond Diode With Nanotip Structure for High-Temperature CO Sensing Applications

The Pd/n-SnO
x
/i-diamond/p-diamond diodes prepared by field-enhanced hot-wire CVD (HWCVD) (FEHWCVD) system on a silicon substrate with nanotip structures are studied systematically. Both the nanotip structure and the better film quality deposited by the FEHWCVD lead the developed p-i-n diamond diode to have a high relative sensitivity ratio of ~ 91% to 100-ppm-carbon monoxide (CO)-gas ambient. The sensitivity ratio is better than 79% compared to the one without the nanotip and prepared by the conventional HWCVD. Thus, the developed p-i-n diamond diode has better potential for high-temperature CO sensing applications.