Controllable Design of Minority Carrier Diffusion in npn Devices for Enhancing Er³⁺-Related Electroluminescence

Al/Er-codoped ZnO films on epitaxial Si substrates are used to fabricate npn heterojunction devices. By controlling the hole concentration in the p -layer of epitaxial Si substrates, the controllable design of the diffusion behavior of minority carriers is achieved, leading to the improvement of the carrier injection of npn heterojunction devices, and the equilibrium between the electron injection and the electric field intensity for acceleration is established. Due to the optimization of the electrical characteristics of devices, the electroluminescence intensity of Er 3+ ions therewith is enhanced by an order of magnitude, resulting in an optical power of 8.26 μW/cm 2 at 1540 nm. Additionally, the unpackaged npn heterojunction devices with an onset voltage of 2 V function continuously for 1400 h in an atmospheric environment with less than 10% optical power attenuation. This technique suggests a prototype device with exceptional photoelectric qualities and high stability, demonstrating its great potential in integrated silicon photonics.