Sensitized electroluminescence from erbium doped silicon rich oxynitride light emitting devices

Abstract

Erbium doped Si-related compound films, with the 1540 nm emission coinciding with the minimum loss window of optical telecommunication, are regarded as appealing platforms of light sources for silicon photonics. In many previous reports, however, the unipolar carrier injection in silicon oxide/nitride films leads to favorable impact excitation of Er rather than sensitization, requiring high onset voltage that is not compatible with Si microelectronics. Silicon rich oxynitride (SRON) with tunable bandgap enables equivalent bipolar injection, yet there are few reports about light emitting devices (LEDs) based on this material with Er doping. Here, sensitized electroluminescence (EL) from erbium doped SRON with an onset voltage as low as 5 V has been demonstrated. The sensitization mechanism is evaluated by correlating the evolution of charge transport in SRON films subjected to different thermal treatments with that of Er3+ EL. The EL can be attributed to bipolar Poole-Frenkel injection of carriers and subsequent capture by Si dangling bond related trap states, followed by energy transfer to Er3+ ions. These results indicate that SRON serves as a promising Er3+ host for complementary metal-oxide-semiconductor (CMOS) compatible light sources.