White electroluminescence in heterostructures based on carbon nanotubes and silicon oxides

This study reports a full area white electroluminescence (EL) emission and an in-depth analysis of the emission spectrum in silicon and carbon-based device configurations. The light-emitting devices are composed of a heterostructure of porous silicon (PSi), carbon nanotubes (CNTs), off-stoichiometric silicon oxide (SiO X ) thin films, and zinc oxide (ZnO) as a top electrode. A three-orders-of-magnitude reduction in emission current consumption has been observed in these devices when compared to conventional electroluminescent devices. Presence of white EL is confirmed by the measured spectra, which exhibits a broad spectrum ranging from 400 to 900 nm. This phenomenon is attributed to the presence of various nanostructured radiative defects within the materials comprising the heterostructures. The carrier transport mechanism in the region where the EL takes place is dominated by space-charge-limited current conduction as indicated by the analysis of the I-V curves. The EL emitted begins at a current level of 60 μA and at approximately 100 μA the highest emission occurs. These findings demonstrate a viable route toward low-power, silicon-compatible white light-emitting devices, with strong potential for solid-state lighting and integrated optoelectronic applications. • The Si-n/PSi/CNT/SiO X /ZnO heterostructures were built and their EL spectra were measured and analyzed. • The emission of white light was achieved with remarkable efficiency at low operating currents, with a current of approximately 60 μA being the minimum required to achieve it, and a current of around 100 μA being the maximum. • The emission exhibits a broad spectral range (400–900 nm) originated from multiple radiative centers associated with porous silicon nanostructures, defect states in SiO X , and intrinsic emissions from CNTs and ZnO. • Electrical analysis confirmed that the dominant transport mechanism in the emission region is governed by SCLC, with trap-assisted tunneling further contributing to carrier injection and radiative recombination.