Electric simulation of silicon drift detector for single photon measurement

The silicon drift detector (SDD) with high quantum efficiency, energy resolution and time resolution is an advanced single photon counting detector in the fields of quantum communication, X-ray communication and pulsar navigation. In this paper we design an optimum SDD structure with circular drift rings and linear-type voltage divider, the device electric characteristics are simulated using a 3D Sentaurus TCAD computational tool including electric potential, electric field, electron concentration, voltage-divider current, leakage current and saturation capacitance. Simulation results are comparable with those of conventional spiral SDDs and other shapes of ring SDDs. The circular ring-shaped structure can generate more even and symmetrical radial electric potential and field distribution, so electrons have shorter and more distinct drift channels, and SDD has ultra-fast time response and good time resolution to detect pulsed single photon signals.