Room Temperature Ammonia Gas Selectivity Studies On SnO_(2) Ultra Thin Film Prepared By Langmuir-Blodgett Technique

摘要

Interaction of various reducing and oxidizing gases with ultrathin SnO_(2) film at room temperature has been studied to investigate the selectivity of SnO_(2) film towards ammonia. SnO_(2) thin films show no response with O_(2), H_(2), CO, ethanol and methane. In presence of H_(2)S and SO_(2) gases conductivity of the film increases where as film conductivity decreases with ammonia and NO_(2). With ammonia gas, the response is fast and > 90percent recovery takes place within 30 min where as with NO_(2)_recovery is partial. The impedance study shows distinctly different frequency dependent responses towards NH_(3) and NO_(2) indicating specificity to ammonia in presence of NO_(2).