Realization of highly efficient hexagonal boron nitride neutron detectors
Here, we report the achievement of highly efficient 10B enriched hexagonal boron nitride (h- 10BN) direct conversion neutron detectors. These detectors were realized from freestanding 4-in. diameter h- 10BN wafers 43 μm in thickness obtained from epitaxy growth and subsequent mechanical separation from sapphire substrates. Both sides of the film were subjected to ohmic contact deposition to form a simple vertical “photoconductor-type” detector. Transport measurements revealed excellent vertical transport properties including high electrical resistivity (>1013 Ω cm) and mobility-lifetime (μτ) products. A much larger μτ product for holes compared to that of electrons along the c-axis of h- BN was observed, implying that holes (electrons) behave like majority (minority) carriers in undoped h- BN. Exposure to thermal neutrons from a californium-252 (252Cf) source moderated by a high density polyethylene moderator reveals that 43 μm h- 10BN detectors possess 51.4% detection efficiency at a bias voltage of 400 V, which is the highest reported efficiency for any semiconductor-based neutron detector. The results point to the possibility of obtaining highly efficient, compact solid-state neutron detectors with high gamma rejection and low manufacturing and maintenance costs.
[1]- Publication Date:
- Grant/Contract Number:
- NA0002927; 2011-DN- 077-ARI048; ECCS-1402886
- Type:
- Accepted Manuscript
- Journal Name:
- Applied Physics Letters
- Additional Journal Information:
- Journal Volume: 109; Journal Issue: 7; Journal ID: ISSN 0003-6951
- Publisher:
- American Institute of Physics (AIP)
- Research Org:
- Texas Tech Univ., Lubbock, TX (United States)
- Sponsoring Org:
- USDOE Office of Nuclear Energy (NE); USDOE National Nuclear Security Administration (NNSA); National Science Foundation (NSF); US Department of Homeland Security (DHS)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; wide bandgap semiconductors; solid-state neutron detector materials; direct conversion neutron detectors; He-3 gap replacement detectors; III-V semiconductors; neutrons; electrons; transport properties; electrical resistivity
- OSTI Identifier:
- 1330680
- Alternate Identifier(s):
- OSTI ID: 1295951