Numerical Analysis of Roles of Depletion Layer Width in Semiconductor Gas Sensor Using the Gradient-Distributed Oxygen Vacancy Model

Abstract

The roles of depletion layer width in semiconductor gas sensors are quantitatively discussed based on the model of gradient-distributed oxygen vacancies. Several literatures are employed to provide experimental basis of the relationship between depletion layer width and gas sensing characteristics of semiconductor devices. Four series of gas sensors are illustrated and their depletion layer widths are controlled by three different techniques, such as controlling of the dopant amount, sintering in various procedures and usage of various dopants. The model shows a good applicability in analyzing the roles of the depletion layer width in semiconductor gas sensors, as long as the grain radius is larger than the depletion layer width, especially when it is controlled by the doping amount of the foreign elements.