Fabrication and performance evaluation of GaN thermal neutron detectors with 6 LiF conversion layer

A GaN-based pin neutron detector with a(6)LiF conversion layer was fabricated, and can be used to detect thermal neutrons. Measurement of the electrical characteristic of the GaN-based pin neutron detector showed that the reverse leakage current of the neutron detector was reduced significantly after deposition of a(6)LiF conversion layer on the detector surface. The thermal neutrons used in this experiment were obtained from an(241)Am-Be fast neutron source after being moderated by 100-mm-thick high-density polyethylene. The experimental results show that the detector with 16.9-mu m thick(6)LiF achieved a maximum neutron detection efficiency of 1.9% at a reverse bias of 0 V, which is less than the theoretical detection efficiency of 4.1% calculated for our GaN neutron detectors.