The Influence of the multilayer ZnO-HfOx structure on the characteristics of a light-emitting device

Abstract

A MOS structure device with a ZnO-HfOx layer was fabricated on a p-type silicon substrate. Current (i.e., conductive) paths formed after the breakdown of the dielectric layer under a voltage and thermal-induced emission of broadband light, including visible and near-IR wavelengths. To investigate the influence of the ZnO-HfOx layer on a device’s light-emitting characteristics, we prepared devices with one, two and three layers of ZnO-HfOx thin film on a p-type silicon substrate. We then measured the light emission, the emission spectrum, the I–V curves and the microstructure. The results show that the range and peak wavelength of the emission spectra from devices with different numbers of ZnO-HfOx layers are the same. Under the condition of a fixed total thickness of HfOx, luminous intensity increases with increasing number of ZnO-HfOx layers. Multilayer ZnO-HfOx can cause the ZnO grains to diffuse more into the HfOx layer, which is beneficial for the formation of current paths and increases the luminous intensity.