Response functions of semiconducting lithium indium diselenide

• Charged particle escape does not significantly affect measured neutron spectra.
• Energetic electron escape affects gamma-induced spectra.
• LISe has a small photoelectric cross section for high energy gamma-rays.
• Excellent gamma/neutron discrimination capability.
• Activated 116In does not readily interfere with 6Li-based neutron signal.

This paper presents the results of a computational investigation that determined the gamma-ray and neutron response functions of a new semiconducting material, 6LiInSe2, which is very sensitive to thermal neutrons. Both MCNP6 simulations and custom post-processing/simulation techniques were used to determine various detection properties of LISe. The computational study included consideration of energetic electron escape, the contribution from the activation of 115In and subsequent decay of 116In, triton and alpha particle escape from the 6Li reaction pathway, and the effect of incomplete charge collection when detecting neutrons via the 6Li reaction pathway. The result of neutron detection with incomplete charge collection was compared to experimental results and showed general agreement, where holes exhibit a lower mobility-lifetime product than electrons, as expected for compound semiconductors.