A neutron detection sheet composed of Ag-doped zinc sulfide (ZnS) as a scintillator and 6LiF asa neutron converter has been conventionally used for neutron detection, and as an imaging detectorusing the photon counting method, because of its high luminescence rate for neutrons. However,the weak point in a Ag-doped ZnS scintillator is the slow component of its lifetime. Thus, webegan to investigate other II–VI compound phosphors without the slow component of its lifetimefor neutron detectors using the photon counting method. In this study, Cu-, In-, Al-, and Gaimpurity-doped ZnO phosphors without the slow component of lifetime for neutron detectors at ahigh counting rate have been fabricated using a spark plasma sintering method. It was found thatGa-doped ZnO exhibited the highest intensity of luminescence at a wavelength of 383 nm. Theintensity of the 383 nm luminescence due to exciton emission with a lifetime of about 4 ns wascomparable to that of the Ag-doped ZnS phosphor with a lifetime of about 220 ns, indicating thatthe Ga-doped ZnO phosphor could be used as a promising phosphor material for a neutron imagesensor. It was also found that the luminescence intensity of the Ga-doped ZnO phosphor samplesdid not decrease when B2O3 was added as a neutron-alpha (n, alpha) converter. It was confirmedthat a Ga-doped ZnO scintillator with B2O3 converter responds to the neutron beam emitted by theJapan Research Reactor-3 (JRR-3).