Characterization of hydrogenated amorphous silicon sensors on polyimide flexible substrate

TL;DR

This paper investigates hydrogenated amorphous silicon sensors on flexible polyimide substrates, focusing on their dosimetric x-ray response, stability, and performance under bending, highlighting their potential for flexible radiation detection applications.

Contribution

It provides a comprehensive characterization of a-Si:H sensors on polyimide, including response linearity, stability, annealing effects, and mechanical flexibility, which was not previously detailed.

Findings

Linear x-ray response with dose-rate

Stable response over time and after annealing

Maintains performance under bending conditions

Abstract

Hydrogenated amorphous silicon (a-Si:H) is a material having an intrinsically high radiation hardness that can be deposited on flexible substrates like Polyimide. For these properties a-Si:H can be used for the production of flexible sensors. a-Si:H sensors can be successfully utilized in dosimetry, beam monitoring for particle physics (x-ray, electron, gamma-ray and proton detection) and radiotherapy, radiation flux measurement for space applications (study of solar energetic particles and stellar events) and neutron flux measurements. In this paper we have studied the dosimetric x-ray response of n-i-p diodes deposited on Polyimide. We measured the linearity of the photocurrent response to x-rays versus dose-rate from which we have extracted the dosimetric x-ray sensitivity at various bias voltages. In particular low bias voltage operation has been studied to assess the high energy efficiency of these kind of sensor. A measurement of stability of x-ray response versus time has been shown. The effect of detectors annealing has been studied. Operation under bending at various bending radii is also shown.