Electronic trap detection with carrier-resolved photo-Hall effect | Science Advances

Electronic trap states critically affect the performance of semiconductor devices such as transistors, memory devices, and solar cells. Yet, conventional trap measurement techniques often require junction fabrication, which can introduce or alter traps. We present a unique photo-Hall–based method to characterize trap density and energy levels while concurrently extracting charge carrier properties. By analyzing photo-Hall conductivity versus electrical conductivity under varying light intensities and temperatures, we uncover an astonishingly simple hyperbola relationship that reveals detailed charge transport and trap occupation and applied it in silicon and halide perovskite films. This technique substantially expands Hall effect–based measurements by integrating electric, magnetic, photon, and phonon excitations into a single framework and enables unparalleled extraction of charge carrier and trap properties, offering a powerful tool for semiconductor characterization and device optimization.