文摘
Under ab initio computations, several new inorganic electride compounds with high stability, M@x-Al12N12 (M = Li, Na, and K; x = b66, b64, and r6), were achieved for the first time by doping the alkali metal atom M on the fullerene-like Al12N12 nanocage, where the alkali atom is located over the Al鈥揘 bond (b66/b64 site) or six-membered ring (r6 site). It is revealed that independent of the doping position and atomic number, doping the alkali atom can significantly narrow the wide gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) (EH-L = 6.12 eV) of the pure Al12N12 nanocage in the range of 0.49鈥?.71 eV, and these doped AlN nanocages can exhibit the intriguing n-type characteristic, where a high energy level containing the excess electron is introduced as the new HOMO orbital in the original gap of pure Al12N12. Further, the diffuse excess electron also brings these doped AlN nanostructures the considerable first hyperpolarizabilities (尾0), which are 1.09 脳 104 au for Li@b66-Al12N12, 1.10 脳 104, 1.62 脳 104, 7.58 脳 104 au for M@b64-Al12N12 (M = Li, Na, and K), and 8.89 脳 105, 1.36 脳 105, 5.48 脳 104 au for M@r6-Al12N12 (M = Li, Na, and K), respectively. Clearly, doping the heavier Na/K atom over the Al鈥揘 bond can get the larger 尾0 value, while the reverse trend can be observed for the series with the alkali atom over the six-membered ring, where doping the lighter Li atom can achieve the larger 尾0 value. These fascinating findings will be advantageous for promoting the potential applications of the inorganic AlN-based nanosystems in the new type of electronic nanodevices and high-performance nonlinear optical (NLO) materials.