l组分渐变增益区低增益雪崩探测器（LGAD）的研究

Low-gain avalanche detector (LGAD) technology is gradually becoming the core of high-energy particle detection in particle colliders due to its strong spatial and temporal resolution and extremely strong radiation resistance. The emergence of the receptor removal effect after high-flux proton or neutron radiation has made LGAD devices increasingly demanding radiation resistance. Gallium nitride has the characteristics of large band gap, high saturated electron drift rate, and good radiation resistance. LGAD devices based on gallium nitride will have better performance in terms of radiation hardness and time resolution. This article uses TCAD software to simulate a low-gain avalanche detector in the Al composition gradient gain region, collects transient characteristic curves, compares them with previously simulated gallium nitride PIN devices, and calculates the gain. The results show that when the multiplication layer thickness is 1.0μm and the charge control layer concentration is 1.04e18cm-3, the gain reaches 52; the impact of the polarization effect is also compared. The addition of the polarization effect increases the gain of the device with a gain of 1.2 to 42.5. It shows that the addition of polarization effect is the main reason why the device produces high gain.