The effect of energy band gap of channel transistor region on npn transistor performance; a numerical study

The distance between conduction and valence bands which is known as bandgap energy is an important factor for semiconductors and is different in various materials. The bandgap energy determines the electrical and optical properties of semiconductors and has a direct effect on the performance of diodes and transistors. In this article, the effect of bandgap energy of the channel region of a npn transistor has been investigated and its effects on capacitance and conductivity, threshold voltage, and the Ion-Ioff ratio were studied. An npn transistor is designed and then the bandgap energy is changed between 0.8 eV and 2.2 eV with a step of 0.2 eV, and subthreshold slope and other electrical quantities have been obtained numerically. By comparing the results, the best performance of the transistor can be obtained. This simulation was done with Silvaco Atlas software. This study can open new windows in design of transistor devices.