High electrical transport performance of C12A7: e(-) ceramics electrides on Cu-doping

(Ca1-xCux) 12A7: e(-) bulks (0 <= x <= 0.05) with electrical performance were fabricated by the in-situ aluminothermic synthesis. The results showed that all the electron concentrations of (Ca1-xCux) 12A7: e(-) reached the theoretical value of about 2.28 x 10(21) cm(-3). In (Ca0.96Cu0.04) 12A7: e(-), the electron mobility at room temperature increased from 3.81 to 5.19 cm(2) V-1 S-1 and the conductivity increased from 415 to 1405 S cm(-1). It indicated that Cu-doping effectively improved electrical properties. The photoexcitation property also changed positively. The energy required for electrons to transition from cage conduction band to frame conduction band showed a decreasing trend, from 2.23 to 1.48 eV. The first-principle calculation showed an upward shift in the Fermi energy level position of C12A7: e(-). In addition, Cu atoms provided more density of states near the Fermi energy level. The number of empty orbitals near the Fermi surface of (Ca1-xCux) 12A7: e(-) that can receive excited electrons increased. It provided a theoretical basis for preparing (Ca1-xCux) 12A7: e(-) with high electrical transport characteristics.