Sub-Pixel Position Sensing And Readout Electronics For Perovskite Low Energy (140 keV) Gamma-Ray Detectors

High spatial and energy resolution gamma detectors are one of the key components for nuclear molecular imaging system. As a novel type of Low Energy Gamma detector, Perovskite detectors possess significant potential, with outstanding material properties such as high stopping power and excellent hole mobility-lifetime product. While it is application for high energy gamma ray detector(${\$}$\sim${\$}$ 661 keV) has been well investigated\cite{he2021cspbbr3}, this study focuses on the optimization design of CsPbBr 3 perovskite gamma ray position and energy sensing for low energy gamma ray (around 140 keV). Sub-pixel position sensing is investigated through simulation and experiments. To handle the low signal amplitude, we designed a front-end circuit comprising input buffering, charge-sensitive preamplification, and second-stage amplification circuits to effectively reduce noise, enhance gain, thus improving the detector’s spatial and energy resolution. Additionally, sub-pixel position sensing theory was validated through simulation experiments. The results demonstrate that by appropriate electronic circuit design and position sensing algorithms, the resolution of perovskite detectors can be significantly improved, promoting their applications in medical imaging fields.