In this paper. we investigate the global existence and large time behavior of entropy solutions to one-dimensional unipolar hydrodynamic model for semiconductors in the form of Euler-Possion equations with time and spacedependent damping in a bounded interval. Firstly. we prove the existence of entropy solutions through vanishing viscosity method and compensated compactness framework. https://www.roneverhart.com/275-55R20-X-FIT-AT/