The annealing of radiation-induced defects in burn-in stressed n-channel power VDMOSFETs with thick gate oxides (100 and 120 nm) is analysed. In comparison with the previous spontaneous recovery, the changes of device electrical parameters observed during annealing are highlighted by the elevated temperature and voltage applied to the gate, and are more pronounced in devices with a 120 nm thick gate oxide. The threshold voltage of VDMOSFETs with a 100 nm thick gate oxide during annealing has an initially slow growth, but then increases rapidly and reaches the value higher than the pre-irradiation one (rebound effect). In the case of devices with a 120 nm thick gate oxide, the threshold voltage behaviour also consists of a slight initial increase followed by a rapid, but dilatory increase, with an obvious tendency to achieve the rebound. The changes of channel carrier mobility during annealing are similar in all samples: at first, it slowly and then rapidly declines, and after reaching the minimum it begins to increase. In the case of VDMOSFETs with a thicker gate oxide, these changes are much slower. The underlying changes in the densities of gate oxide-trapped charge and interface traps are also delayed in devices with a thicker gate oxide. All these phenomena occur with certain delay in burn-in stressed devices compared to unstressed ones. The leading role in the mechanisms responsible for the observed phenomena is attributed to hydrogen related species.

In the course of the last few years, interest in the development of smart cities and progress of smart buildings has increased significantly. This development has been significantly increased due to the development of new technologies, innovative functional materials, electronic components and other products. At the same time, it is imperative to use those products that contribute to the preservation of the environment, and above all to energy saving. Thus, new technologies are becoming increasingly attractive, such as the one based on OLED (Organic Light Emitting Diode) technology, which is used in the production of mobile phones, tablet computers, other devices, as well as light sources. Although this technology has been generally known for more than half a century, commercial application of OLED components was not possible due to insufficient efficiency of products based on it. However, the continuous improvement of characteristics and efficiency enabled their more significant application in the past few years. The aim of this work is to provide adequate information about the possibilities of applying some innovative technologies in the planning and development of smart cities. Especially, becoming more familiar with the basic properties and application possibilities of OLED devices can lead to the life quality improvements of city spaces users.