Precisely Control the Component Ratio to Achieve Highly‐Efficient Electroluminescence From Er‐Doped Perovskite MgGeO ₃ Nanofilms

ABSTRACT Based on previous achievement in the fabrication of silicon‐based perovskite MgGeO 3 and olivine Mg 2 GeO 4 nanofilms using atomic layer deposition, the electroluminescence (EL) properties of these matrices doped with Er 3+ ions are explored. The dopant Er 2 O 3 atomic layers influence the growth of MgO/GeO 2 nanolaminates, as evidenced by the increased Mg/Ge ratio and the difference in resultant lattice structure. Er 3+ ions are proven to preferentially occupy the octahedral sites, thereby increases octahedron/tetrahedron ratio in the lattice and are conducive to the formation of the Mg 2 GeO 4 structure. The perovskite MgGeO 3 is superior to olivine Mg 2 GeO 4 as the EL matrix, the electrical injection and excitation efficiency of perovskite MgGeO 3 :Er nanofilms are significantly higher than olivine Mg 2 GeO 4 :Er ones. Adjusting the matrix recipes using different Mg/Ge ratios or MgO cycles in each supercycle also yields the above‐mentioned EL difference that determined by the lattice structure. The EL device using amorphous MgGeO 3 :Er nanofilm achieves a high external quantum efficiency of 20.9% and a power density of 7.88 mW cm −2 , and could operate for up to 2.43 × 10 4 s. This work explicates the importance of precisely control of the components in MgO/GeO 2 /Er 2 O 3 nanolaminates for achieving efficient EL from perovskite MgGeO 3 :Er nanofilms, and demonstrates their potential applications in silicon‐compatible optoelectronics.