High electrical transport performance of C12A7: e– ceramics electrides on Cu‐doping

Abstract

Abstract(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 × 1021 cm–3. In (Ca0.96Cu0.04) 12A7: e–, the electron mobility at room temperature increased from 3.81 to 5.19 cm2 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.