Direct detection of 5-MeV protons by flexible organic thin-film devices

Abstract

The direct detection of 5-MeV protons by flexible organic detectors based on thin films is here demonstrated. The organic devices act as a solid-state detector, in which the energy released by the protons within the active layer of the sensor is converted into an electrical current. These sensors can quantitatively and reliably measure the dose of protons impinging on the sensor both in real time and in integration mode. This study shows how to detect and exploit the energy absorbed both by the organic semiconducting layer and by the plastic substrate, allowing to extrapolate information on the present and past irradiation of the detector. The measured sensitivity, S = (5.15 ± 0.13) pC Gy−1, and limit of detection, LOD = (30 ± 6) cGy s−1, of the here proposed detectors assess their efficacy and their potential as proton dosimeters in several fields of application, such as in medical proton therapy.

Radiation-Tolerant Proton Detector Based on the MAPbBr3 Single Crystal

“…Figure f shows the linear response of the current to the fluence rate of protons, which indicates that the detector could monitor the fluence rate in real time. The limit of detection (LOD), as calculated using the method mentioned in the previous study, was found to be about 2.07 × 10 10 p cm –2 s –1 at −10 V. The LOD increased along with the bias voltages due to the increased dark current, as shown in Figure S3. This detection limit could be further improved if the dark current could be further lowered by, for instance, compensation doping, using a guard ring electrode, surface polishing, or using a wider band gap perovskite, such as MAPbCl 3 . ,, …”

“…(b) Normalized dark current of the detector at −10 V as a function of the proton fluence; the dashed line is the fitting curve. (c) Comparison of the performance degradation for the MAPbBr 3 detector and other reported semiconductor proton detectors (Si, TIPGe–Pn, diamond, and TlBr). The data points of diamond are proton-induced currents.…”

“…For instance, for a conventional silicon detector, its dark current could increase by an order of magnitude after 10 13 p cm –2 proton (3 MeV) irradiation . Similarly, for a recently reported new-type detector based on the organic semiconductor, its dark current was found to increase by more than 20 times after only 4 × 10 11 p cm –2 proton (5 MeV) irradiation . As a result, these short-life-time detectors cannot meet the increasingly stringent demands of the proton detection in high-energy physics experiments and proton therapy. , Therefore, it is imperative to develop next-generation proton detectors with particularly high radiation tolerance.…”

Direct Detection of Fast Neutrons by Organic Semiconducting Single Crystal Detectors

“…The compact detector could be placed at specific position of human body for highly-localized, accurately monitoring the absorbed neutron flux by the target position. [6,14] This could never be achieved by conventional bulky detection facilities. Kargar et al reported that an organic semiconductor detector based on solution-grown perylene (C 20 H 12 ) showed a response (signals above the electronic noise) to fast neutrons emitted from a 24l Am-Be source.…”

“…[ 5 ] In this application, the difficulty is accurately monitoring the beam (flux and energy) absorbed by the tumor position, which requires a fast neutron detector with not only dose and energy discrimination abilities, but also specific properties including tissue‐equivalence and highly‐localization. [ 6 ] These fantastic applications present tremendous requirements for fast neutron detectors. However, fast neutron cannot be detected directly by almost all inorganic semiconductors because their zero‐charge property makes them cannot directly interact with the semiconductor via ionization, thus their detection is more difficult than other charged radiations.…”