Semiconductor-based diodes for tritium detection

In order to plan an experimental betavoltaic detection process of tritium using 4H-SiC diodes, we have performed a preliminary numerical Monte-Carlo investigation. In a first part, by evaluating the transparency of several materials to the electrons produced by tritium decay, we have shed light on: (i) the necessity to place the detection diode in close neighborhood of the tritiated sample (less than 1mm distance) or to work in vacuum, (ii) the importance to use very thin coating layers (less than 0.1μm), containing low density materials, (iii) the strong screening effect of 4H-SiC (0.4μm thickness of 4H-SiC divides the intensity flux by 4). In a second part, we have built a deposition energy cartography in PIN and Schottky diodes, confirming that the upstream surface part of the diode (less than 0.5μm depth layers) will constitute the detection region.