Amorphous silicon-based detectors for high-energy particle detection"
N. Wyrsch, nicolas.wyrsch@epfl.ch,
Laboratory of photovoltaics and thin-films electronics (PV-lab)
Institute of Electrical an Microengineering (IEM)
Ecole Poytechnique Fédérale de Lausanne (EPFL)
Hydrogenated amorphous silicon (a Si:H) is one of the most radiation-resistant semiconductors and therefore is an attractive material for the fabrication of particle sensors. The fact that this material can be deposited on various types of substrates and alloyed with other elements to modify its properties is another crucial advantage. a-Si:H has been successfully implemented in large-area particle detectors for X-ray radiography using an indirect detection scheme but has failed to be used in experiments or systems relying on a direct detection scheme. One of the reasons was the failure to demonstrate single-particle detection.
In this presentation, after an overview of the main properties of a-Si:H and of its related deposition technique, I will review the development of a Si:H based particle detectors and strategies aiming at minimum ionizing particles (MIPS) and single particle detection. I will discuss the fundamental limits and bottlenecks and show possible solutions to finally achieve such detection. Recent developments on the vertical integration of thick a-Si:H diode array on top of a readout ASIC (so-called “thin-film on ASIC” or “TFA” technology), on vertically integrated micro-channel plates (MCP) and 3D detectors will be presented and discussed.