ZnO Homojunction Based BTX Vapor Sensor Device

In the present work ZnO homojunction based vapor sensor device for the detection of benzene, toluene and xylene at room temperature is reported. ZnO homojunction is fabricated by depositing p-type (sodium doped) ZnO nanoparticles on top of ntype ZnO nanotube. FESEM images authenticated the formation of nanostructured nanotubes and nanoparticles. The current-voltage characteristic of the homojunction showed rectifying characteristics in presence of target vapors and air. The homojunction device was able to detect even low ppm (5 ppm) of benzene vapor with a good selectivity with its other interfering species (toluene and xylene) at room temperature owing to the advantage provided by formation of device junction. The homojunction device also demonstrated a good selectivity of benzene in comparison with its other interfering species (toluene and xylene) in low concentration range (5 – 50 ppm).