Metal-semiconductor-metal (MSM) detectors based on Ti/Au and Ni/Au interdigitated structures were fabricated using 2.5 micrometer thick hexagonal boron nitride (h-BN) layer with both natural and 10B-enriched boron. Current-voltage (I-V) and current-time (I-t) curves of the fabricated detectors were recorded with (IN) and without (Id) neutron irradiation, allowing the determination of their sensitivity (S = (IN - Id)/Id = ΔI/Id). Natural and 10B-enriched h-BN detectors exhibited high neutron sensitivities of 233 and 367% at 0 V bias under a flux of 3 × 104 n/cm2/s, respectively. An imbalance in the distribution of filled traps between the two electric contacts could explain the self-biased operation of the MSM detectors. Neutron sensitivity is further enhanced with electrical biasing, reaching 316 and 1192% at 200 V and a flux of 3 × 104 n/cm2/s for natural and 10B-enriched h-BN detectors, respectively, with dark current as low as 2.5 pA at 200 V. The increased performance under bias has been attributed to a gain mechanism based on neutron-induced charge carrier trapping at the semiconductor/metal interface. The response of the MSM detectors under thermal neutron flux and bias voltages was linear. These results clearly indicate that the thin-film monocrystal BN MSM neutron detectors can be optimized to operate sensitively with the absence of external bias and generate stronger signal detection using 10B-enriched boron.
KAUST Repository Item: Exported on 2022-01-25
Acknowledged KAUST grant number(s): OSR-2018-CRG7-3771.2
Acknowledgements: This study was partially funded by the French National Research Agency (ANR) under the GANEX Laboratory of Excellence (Labex) project and the KAUST Competitive Research Grant under grant no. OSR-2018-CRG7-3771.2 as well as the Grand Est Region in France. The authors gratefully acknowledge Stephanie Sorieul, Mourad Aiche, and Ludovic Mathieu from CENBG for their help on the neutron testing.