TCAD simulation of the electrical properties of a novel meander strip electrode pixel High-Purity Germanium detector

Abstract High-purity germanium (HPGe) detectors, serving as crucial devices that convert radiation signals into electrical signals, are characterized by their wide detection range and high energy resolution, which makes them widely applicable in fields such as nuclear physics research and aerospace. HPGe detectors require a large sensitive area thickness to achieve a broad energy detection range. However, the incomplete charge collection becomes more pronounced due to the large size of HPGe detectors. Furthermore, the limited position resolution of large-size detectors greatly hinders the advancement of HPGe detectors. To improve the electrical performance of HPGe detectors in radiation detection applications, this study introduces a new strategy. By designing HPGe detectors as small-size pixel units with meander strip electrodes, we shorten the distance between the cathode and anode. Integrating multiple such units into a detector array enables the detector to improve position resolution capability. The electrical performance of this detector structure was simulated using the semiconductor device simulation software Sentaurus TCAD, and the heavy ions incidence process on the detector array was also modeled. The simulation results consistently indicate that the pixel HPGe detector with meander strip electrode exhibits good electrical performance, charge collection efficiency, and fast response time. Compared to the coaxial HPGe detector with a diameter of 50 mm reported in previous literature, which has a depletion voltage of 1800 V, the pixelated HPGe detector proposed in this paper features a significantly lower full depletion voltage, with a value of -5 V. This study offers a novel approach to enhancing the performance of HPGe detectors and broadens their application scenarios.