Electron/hole traps alter the optical and electrical properties of materials by creating additional recombination pathways, trapping or providing charge carriers and modifying exciton dynamics. Understanding the defect/trap dynamics is crucial to control the optoelectronic properties of materials, and measuring donor/acceptor ionization energy is critical in semiconductor research. Here, we developed a highly sensitive thermally stimulated emission (TSE) spectrometer for the low temperature regime of 9–325 K to detect and characterize shallow traps in bandgap materials with enhanced sensitivity. It provides a powerful characterization tool for a wide range of semiconductors and electronic and photonic materials. This technique is ideal where electrical methods cannot be used for donor/acceptor characterization as in powder, irregular shape and thickness, and high resistive samples.