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Abstract

The influence of ion implantation on the structure and properties of polymers is a very complex issue. Many physical and chemical processes taking place during ion bombardment must be taken into consideration. The complexity of the process may exert both positive and negative influence on the structure of the material. The goal of this paper is to investigate the influence of H+, He+ and Ar+ ion implantation on the properties of polypropylene membranes used in filtration processes and in consequence on fouling phenomena. It has appeared that the ion bombardment caused the chemical modification of membranes which has led to decrease of hydrophobicity. The increase of protein adsorption on membrane surface has also been observed.

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Authors and Affiliations

Karolina Kotra-Konicka
Joanna Kalbarczyk
Jakub M. Gac
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Abstract

The aim of this article is to present the results of research aimed at confirmation whether it is possible to form an intermediate band in GaAs implantation with H+ ions. The obtained results were discussed with particular emphasis on possible applications in the photovoltaic industry. As it is commonly known, the idea of intermediate band solar cells reveals considerable potential as the most fundamental principle of the next generation of semiconductors solar cells. In progress of the research, a series of GaAs samples were subjected to poly-energy implantation of H+ ions, followed by high-temperature annealing. Tests were conducted using thermal admittance spectroscopy, under conditions of variable ambient temperature, measuring signal frequency in order to localize deep energy levels, introduced by ion implantation. Activation energy ΔE was determined for additional energy levels resulting from the implantation of H+ ions. The method of determining the activation energy value is shown in Fig. 2 and the values read from it are σ0 = 10−9 (Ω·cm)−1 for 1000/T0 = 3.75 K−1 and σ1 = 1.34 × 10−4 (Ω·cm)−1 for 1000/T1 = 2.0 K−1. As a result, we obtain ΔE ≈ 0:58 eV. It was possible to identify a single deep level in the sample of GaAs implanted with H+ ions. Subsequently, its location in the band gap was determined by estimating the value of ΔE. However, in order to confirm whether the intermediate band was actually formed, it is necessary to perform further analyses. In particular, it is necessary to implement a new analytical model, which takes into consideration the phenomena associated with the thermally activated mechanisms of carrier transport as it was described in [13]. Moreover, the influence of certain parameters of ion implantation, post-implantation treatment and testing conditions should also be considered.

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Authors and Affiliations

Paweł Węgierek
Justyna Pietraszek
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Abstract

Thiswork presents results of comparative studies of the optical absorption coefficient spectra of ion implanted layers in silicon. Three nondestructive and noncontact techniques were used for this purpose: spectroscopic ellipsometry (SE), modulated free carriers absorption (MFCA) and the photo thermal radiometry (PTR). Results obtained with the ellipsometric method are the proof of correctness of the results obtained with the MFCAandPTRtechniques. These techniques are usually used for investigations of recombination parameters of semiconductors. They are not used for investigations of the optical parameters of semiconductors. Optical absorption coefficient spectra of Fe+ and Ge+ high energy and dose implanted layers in silicon, obtained with the three techniques, are presented and compared.

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Authors and Affiliations

Krzysztof Dorywalski
Łukasz Chrobak
Mirosław Maliński

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