Thermal neutron irradiation experiments on 10BP single-crystal wafers

The electrical properties of 10 BP wafers grown by chemical vapour deposition at room temperature before and after irradiation by thermal neutrons were measured by the van der Pauw method. No appreciable change in electrical properties was observed for the (100) wafer. In the case of the (111) wafer, the carrier concentration for the n type increased and decreased for the p type after irradiation with thermal neutrons owing to the formation of donors caused by nuclear reaction of 10 B(n,α) 7 Li. The electrical conductivity σ, the carrier concentration n and the mobility μ of the (111) wafer after irradiation were measured at high temperatures: n decreased and μ increased for the p type (and vice versa for the n type) compared with the values before irradiation. The temperature dependence of carrier concentration before and after irradiation was correlated with the theoretical curves to calculate the donor and acceptor concentrations and their activation energies.