Low Gain Avalanche Diodes (LGADs) are silicon detectors that utilize the impact ionization process to achieve gain values of ~10. While LGADs have been optimized for high precision timing (σt∼30 ps) in charged particle detection, standard gain-layer segmentation typically limits the fill factor due to significant “dead area” between pixels.

Trench-Isolated Low Gain Avalanche Diodes (TI-LGADs) is an alternative technological approach to achieve fine segmentation in LGADs. Developed by FBK, this technology replaces traditional junction termination extension (JTE) and p-stop with sub-micron trenches (<1 µm) filled with dielectric material (SiO2). This innovation reduces the nominal inter-pixel no-gain width from the standard 30–80 µm to less than 3 µm, enabling a fill-factor of nearly 80% for a 50 µm pitch sensor. Furthermore, TI-LGAD sensors manufactured with a double-sided process hold promise for soft X-ray detection. They can provide a reasonably high fill factor, small pixels down to 25 µm, and simultaneously offer the possibility to integrate an entrance window on the sensor backside.

Next-generation X-ray telescopes require significantly higher quantum efficiency across the soft X-ray band to observe faint celestial objects—capabilities that current CCD or SDD-based detectors struggle to meet. By coupling TI-LGADs with the custom XPOL-III readout ASIC, this integrated system can achieve microsecond timing resolution and extend sensitivity to low-energy photons (∼1 keV). The result is a comprehensive 5D resolution solution for the next generation of space-based ionizing radiation detection.

The successful candidate will be involved in the development and characterization of the TI-LGADs with an optimized entrance window on the sensor backside. The main activities of this position will be focused on:
· the characterization of sensors using infrared/visible, x-ray and gamma radiation, as well as charged particles; these tasks will be mainly performed in the laboratories of FBK;
· development and optimization of new characterization setups.