The electronic structures and work functions of (100) surface of typical binary and doped REB 6 single crystals

•The crystal electronic structures and work functions of single crystal REB6 were systematically studied.•REB6 exhibits the large DOS near Fermi level and d elections of RE element contribute the electronic states of election emission.•The calculated results show that the REB6 (RE=La, Ce, Gd) have lower work function.•Doping suitable RE elements with active d orbital electrons can significantly reduce work function of REB6.•First principles calculation could provide a good theoretical guidance for the study of electron emission properties of REB6.