Dirkjan Verheij – AIM Fellow 2018

Personal info: I obtained my master degree in engineering physics in 2017 at Instituto Superior Técnico. Afterwards I continued my work developed during my master thesis under a scholarship at CTN, being part of the Laboratório de aceleradores e técnicas de radiação (LATR) group and in collaboration with INESC-MN. Currently a PhD student of the AIM doctoral program (started 1st of September of 2018).

Project Resistant and Flexible GaN radiation sensors

Supervisors Dr. Katharina Lorenz (inesc-mn and LATR/CTN), Prof. Dr. Susana Cardoso (INESC-MN) and Dr. Jorge Fernandes (INESC-ID).

Abstract Small, flexible and robust sensors for ionizing radiation could mitigate the risk of damaging healthy tissue during radiotherapy by locally monitoring the applied radiation dose. This project aims at the development of radiation sensors based on GaN nano-and microwires which are expected to withstand high radiation doses delivering reliable dosimetry data in real time. Different sensor geometries will be tested incorporating axial or core-shell p-n junction wires. Single-wire devices will allow studying in-depth the physical processes occurring during photon or particle detection as well as optimising the electrical contacts. Arrays of multiple-wire devices will be processed on conventional and flexible substrates. All sensors will be tested for the detection of UV, X-ray and gamma photons as well as high energy particles. The most promising sensors will be integrated into a flexible printed circuit board for signal amplification and processing and tested in a phantom mimicking human tissue.

Project goals
1. Fabrication and test of radiation sensors with different designs;
2. Integration of most promising structures into arrays and flexible substrates;
3. Sensor integration into circuit boards and testing of the sensors in a phantom mimicking human tissue.


(prior to aim)
“Radiation sensors based on GaN microwires”, D Verheij et al 2018 J. Phys. D: Appl. Phys. 51 175105
Conferences (prior to aim):
“Radiation sensors based on GaN microwires”, poster presentation at 20th edition of the Surface
Modification of Materials by Ion Beams (SMMIB), awarded with a young researcher award for best poster.
“Radiation sensors based on GaN microwires grown by MOVPE”, oral presentation at the 1st Iberian
Meeting on Materials Science.