Barrier-cluster-heating model of disordered semiconductors was originated by synthesis of the barriercluster model (which was described in the previous works of authors) and of the local heating model (published short time ago). The synthesis of these two models brought synergic effect enabling deeper understanding of physical processes in amorphous semiconductors. The article gives a new view on the essence of some optical and photoinduced effects in chalcogenide glasses on the base of the barrier-cluster-heating model.

No abstract

The paper deals with the problem of decreasing level of knowledge of university students due to the changes of the school system in Slovakia. As the commonly repeated words connected with education in 21st.century are key competencies, we tried to look at the problems and challenges in teaching physics from this point of view. The role of classical experiments in our computerized world is also discussed.

In this article we present a different view on the results of experimental investigation of the self - diffusion on Pd (111) published in „Surface Science“ [1]. Our consideration is based on the band model of diffusion. This model is able to explain the Meyer-Neldel rule (MNR) and to clarify “puzzles” mentioned in [1]. The aim of this article is also to familiarize the readers with this model, to the band model of diffusion.

Although hydrogenated amorphous silicon has its important practical application there still is not any generally accepted model explaining all the physical phenomena ongoing in this matter. The aim of this paper is to familiarize the reader with a model allowing to explain the empirically observed compensation effect (Meyer-Neldel rule-MNR). This effect reflects the correlation between activation energy and pre-exponential factor in relation to the activation dependence of electrical conductivity of semiconductors, including a-Si:H. The model assumes that the recombination of carriers is conditioned by emission of series of monoenergetic phonons. The number of emitted phonons is dependent on the activation energy of disordered semiconductor, which influences the probability of recombination and thus the concentration of free electrons. Consideration of the relationship between compensation effect and Urbach rule is also presented.