Room temperature electroluminescence from ZnO/Si heterojunction devices grown by metal–organic chemical vapor deposition

Heterojunction light-emitting diodes with ZnO/Si structure were fabricated on both high-resistivity (p) and low-resistivity (p+) Si substrates by metal–organic chemical vapor deposition technology. Fairly good rectifications were observed from the current–voltage curves of both heterojunctions. Ultraviolet (UV) and blue-white electroluminescence (EL) from ZnO layer were observed only from ZnO/p+-Si heterojunction under forward bias at room temperature (RT), while strong infrared (IR) EL emissions from Si substrates were detected from both ZnO/p-Si and ZnO/p+-Si heterojunctions. The UV and IR EL mechanisms have been explained by energy band structures. The realization of RT EL in UV–visible and IR region on Si substrate has great applicable potential for Si-based optoelectronic integrated circuits.