Abstract: Even minor defects in semiconductor material will effectively affect its photoelectric properties，and different types of defects have different effects. In this paper，we use different methods of mathematical physics to solve continuity equation of semiconductor physics，and demonstrate the results with GUI tool by the Matlab software. The influences of defects on the spatial distribution of carrier under different illuminations，for example, local illumination and uniform global illumination，are shown in this GUI. After setting the related parameters and the subsequent demonstration，this GUI is helpful to guide the undergraduate students to understand the application of mathematical physics method，and allow them to gain a more intuitive learning experience in studying the semiconductor physics.

Key words: defects, carrier concentration, temporal evolution, diffusion length