Uncovering 0D and 1D Electrides with Low Work Function in a Sc-P System

Electrides have drawn much interest in recent years due to their high carrier mobility, low work function, and exotic catalytic performance. Inspired by the discovery of diverse high pressure electrides, here we investigated the potential electrides in the Sc-P system under high pressure. Through extensively unbiased structure searches, Sc5P3_P63/mcm was newly found to be robustly stable at ambient and high pressure, whereas ScP3_Pmc21, ScP2_C2/m, ScP_R-3m, Sc2P_Cmce, Sc2P_P63/m, and Sc3P_Pm-3m were found to be stable under high pressure. Atomic-scale voids in Sc6 octahedra are formed in Sc5P3_P63/mcm, Sc3P_Pm-3m, and Sc3P_Pnma. By analyzing the electronic structure, high electron accumulations can be observed in the voids, which act as anionic electrons. Especially, Sc5P3_P63/mcm is verified to be 1D electride, with anionic electrons confined in the channel voids along the z axis, while Sc3P_Pm-3m and Sc3P_Pnma are 0D electrides. The calculated lowest work functions of Sc5P3_P63/mcm and Sc3P_Pm-3m are 2.64 and 2.57 eV, respectively, comparable to those of Ca2N and LaScSi. The low work function and special stability suggest that they are potential materials in electron emitters and catalyst applications.

Automated summary

Electrides have gained significant attention for their high carrier mobility, low work function, and unique catalytic performance. In this study, we investigated potential electrides in the Sc-P system under high pressure and discovered stable 1D and 0D electrides with high electron accumulations in voids. These electrides exhibit low work functions, suggesting their potential applications in electron emitters and catalysts.