Systematical, experimental investigations on LiMgZ (Z = P, As, Sb) wide band gap semiconductors

This work reports on the experimental investigation of wide band gap compounds LiMgZ (Z = P, As, Sb), which are promising candidates for opto-electronics and anode materials for lithium batteries. The compounds crystallize in the cubic (C1(b)) MgAgAs structure (space group F (4) over bar 3m). The polycrystalline samples are synthesized by solid-state reaction methods. X-ray and neutron diffraction measurements show homogeneous, single-phased samples. The electronic properties are studied using the direct current method. Additionally, UV-Vis diffuse reflectance spectra are recorded in order to investigate the band gap nature. The measurements show that all compounds exhibit semiconducting behaviour with direct band gaps of 1.0-2.3 eV depending on the Z element. A decrease in the peak widths in the static Li-7 nuclear magnetic resonance spectra with increasing temperature is observed, which can be directly related to an increase in Li ion mobility.