A carbon nanotube based x-ray detector

Abstract

X-ray detectors based on metal-oxide semiconductor field effect transistors couple instantaneous measurement with high accuracy. However, they only have a limited measurement lifetime because they undergo permanent degradation due to x-ray beam exposure. A field effect transistor based on carbon nanotubes (CNTs), however, overcomes this drawback of permanent degradation, because it can be reset into its starting state after being exposed to the x-ray beam. In this work the CNTs were deposited using a dielectrophoresis method on SiO coated p-type (boron-doped) Si substrates. For the prepared devices a best gate voltage shift of 244 V Gy and a source-drain current sensitivity of 382 nA Gy were achieved. These values are larger than those reached by the currently used MOSFET based devices.

Indirect X-ray Detectors Based on Inkjet-Printed Photodetectors with a Screen-Printed Scintillator Layer

“…Several works have explored the use of PDs for indirect X-ray detection based either on polymer thin films filled with scintillator and fluorescent molecules, , inorganic high- Z nanocomposites, or carbon nanotubes to enhance the sensitivity to X-rays and consequently reduce the radiation dose. However, consistent approaches are still required to reach unfailing and reproducible deposition of multilayer stacks of different functional materials.…”

“…Polymer composites based on scintillator nanoparticles allow the design and overcome such limitations as well as innovative, novel applications, thanks to their high efficiency, flexibility, and low-cost production. 35 Several works have explored the use of PDs for indirect X-ray detection based either on polymer thin films filled with scintillator and fluorescent molecules, 35,36 inorganic high-Z nanocomposites, 37 or carbon nanotubes 38 to enhance the sensitivity to X-rays and consequently reduce the radiation dose. However, consistent approaches are still required to reach unfailing and reproducible deposition of multilayer stacks of different functional materials.…”

Numerical and experimental study of radiation induced conductivity change of carbon nanotube filled polymers

“…X-rays are used in medical applications such as radiation therapy and diagnostic radiology [1][2][3][4][5]. For therapy applications, x-ray doses delivered to a subject must be carefully controlled as demanded, or the over exposed x-ray would result in harmful side effects.…”