AC-Driven Ultraviolet-B Electroluminescence From Gd3+-Doped ZnGa2O4 Film on SiOx/Silicon Substrate

Ultraviolet (UV) light sources with wavelengths ranging from 100 to 400 nm are of fundamental interest in a wide range of applications, such as water purification, UV communication, disinfection, and sterilization. This heartens the development to provide UV light sources derive from different approaches. Here, we present UV-B electroluminescence (EL) from Gd
³⁺
-ZnGa
₂
O
₄
(ZGO:Gd
³⁺
) that formed in silicon substrate through a one-step annealing method. Structurally, it consists of two oxide layers; amorphous SiO
_x
as an interfacial layer and ZGO:Gd
³⁺
as a UV-B emitting layer, a so-called metal-oxide-semiconductor (MOS) structure. Under applied sinusoidal waveform, the device emits a sharp UV-B spectrum and increases gradually under voltage variations without any spectral change. We show that our device has asymmetrical optical transient behavior due to the asymmetric two oxides layer across the MOS-EL device.