Pentacene Coated Atop of Ultrathin InN Gas Sensor Device for the Selective Sensing of Ammonia Gas for Liver Malfunction Application

Abstract

An ultrathin InN resistive gas sensor is used for selective sensing of ammonia gas by using (∼5nm) pentacene film coating on the InN epilayer for liver malfunction applications. In order to distinguish between ammonia and acetone gases in the exhaled breath, we used two physically different characteristics of InN epilayer such as bare InN epilayer and thin pentacene film atop InN epilayer. On the bare InN epilayer, current variation responses for 8ppm ammonia and 8ppm acetone were 0.6% and 0.57% respectively. On bare InN epilayer, the current variation response of ammonia gas is only 1.05 times the current variation response of acetone gas. On pentacene coated InN epilayer current variation responses for 8ppm ammonia and 8ppm acetone gases are 4.7% and 1.9% respectively. The current variation response for ammonia is 2.47 folds higher than acetone on the pentacene coated InN epilayer. A thin film pentacene atop InN epilayer is very effective to filter out the acetone gas. Therefore, pentacene coated atop ultrathin InN epilayer is useful for the selective sensing of the ammonia gas in the exhaled breath for liver malfunction applications.