Silicon diodes with large aspect ratio perforated microstructures backfilled with 6LiF show a dramatic increase in neutron
detection efficiency beyond that of conventional thin-film coated planar devices. Described in this work are
advancements in the technology with increased microstructure depths and detector stacking methods that work to
increase thermal-neutron detection efficiency. Models for ion energy deposition and intrinsic thermal-neutron detection
efficiency for the straight trench design are described and results presented. A dual stacked device was fabricated by
coupling two detectors back-to-back, along with counting electronics, into a single detector. Experimentally verified
results and modeled predictions are compared. The stacked device delivered 37% intrinsic thermal-neutron detection
efficiency, lower than the predicted value of 47%. It was determined that this lower observed efficiency is due to
detector misalignment in the stacked structure and ballistic deficit from slow charge collection from the deep trench
structures. The intrinsic thermal-neutron detection efficiency depends strongly upon the geometry, size, and depth of the
perforated microstructures. This work is part of on-going research to develop solid-state semiconductor neutron detectors
with high detection efficiencies.
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