Detective Quantum Efficiency (DQE) is one of the most important image quality metrics for evaluating the spatial
resolution performance of flat-panel x-ray detectors. In this work, we simulate the DQE of amorphous selenium (a-Se) xray
detectors with a detailed Monte Carlo transport code (ARTEMIS) for modeling semiconductor-based direct x-ray
detectors. The transport of electron-hole pairs is achieved with a spatiotemporal model that accounts for recombination
and trapping of carriers and Coulombic effects of space charge and external applied electric field. A range of x-ray
energies has been simulated from 10 to 100 keV. The DQE results can be used to study the spatial resolution
characteristics of detectors at different energies.