Kassa Endalamaw Ewnu

Title : Sensing mechanism elucidation and performance optimization of perovskite-based gas sensors for ammonia gas detection

Abstract:

Understanding the sensing mechanism is crucial for optimizing perovskite-based sensors, such as MAPbI3. Despite stability challenges, our study reveals a consistent increase in current during varying concentrations of ammonia. The interaction involves the reduction of MA⁺ to MA and the oxidation of NH3 into NH4⁺, forming a cation exchange mechanism. This process enhances carrier concentration, boosting electrical conductivity. The smaller ionic radius of NH4⁺ facilitates effective cation exchange, while the electron lone pair of the nitrogen atom in alkylamine molecules permeates the perovskite structure, leading to improved conductivity. Our study addresses gaps in understanding perovskite-based gas sensors, providing insights into the complex sensing mechanism of MAPbI₃ during ammonia detection.

Biography:

Endalamaw Ewnu Kassa is currently pursuing a master’s degree in electronic engineering (MSc) at Ming Chi University of Technology (MCUT) in Taiwan, building on his prior educational background with a bachelor’s degree in physics (BSc) from Wollo University in Ethiopia. In January 2022, he joined organic electronic research group at MCUT, Taiwan. He is keenly exploring the realms of perovskite-based gas sensor technology, organic photodetectors (OPD), and light-emitting diodes (LED). From 2017 to 2021, he served as an assistant lecturer and assistant lab technician, accumulating valuable professional experience in academia.