Dose-varied tungsten ion implantation for performance modulation of GA2PbI4 x-ray detectors

This study investigates the performance modulation of GA2PbI4 perovskite single crystals for x-ray detection via W ion implantation at varied doses. All implanted samples exhibit improved carrier transport and enhanced charge dynamics. The sample implanted with a moderate dose of 5 × 1016 ions/cm2 shows a relatively low trap density of 5.35 × 108 cm−3, a high μτ product of 3.46 × 10−3 cm2 V−1, and an enhanced PL intensity with prolonged lifetimes, indicating partial defect passivation and suppressed non-radiative recombination. Its x-ray response time is also reduced by nearly 50% compared to the pristine sample. Density functional theory and time-dependent density functional theory calculations reveal that moderate W implantation introduces shallow donor states near the conduction band minimum, enhances dielectric polarization, and modulates charge redistribution in the Pb–I framework, in agreement with the experimental improvements. As a result, this sample achieves the most balanced and optimal performance, with ∼20% higher x-ray detection sensitivity than the pristine device.