Ulrich Kentsch

Head Implanter
Phone: +49 351 260 3345

Publications - Ion implantation and modification of materials

Here you are finding current publications that have emerged from user experiments and collaborations with the "Ion implantation and modification of materials" group.

Publikations FWIZ-I

Year >= 2018
"Online First" included
OU: Implanter (FWIZ-I)

Impact of low energy ion beam on the properties of rr-P3HT films

Kislyuk, V.; Kotrechko, S.; Trachevskij, V.; Melnyk, A.; Pud, A.; Ogurtsov, N.; Noskov, Y.; Osiponok, M.; Lytvyn, P.; Dzyazko, Y.; Nierobisch, F.; Schneider, A.; Ludewig, F.; Akhmadaliev, S.; Aniol, R.; Kentsch, U.; Krause, M.; Facsko, S.

Two types of ions (fluorine and titanium) are implanted into films of regio-regular poly(3-hexylthiophene-2,5-diyl) (rr-P3HT) spin-coated on glass substrates with subsequent annealing in argon atmosphere to modify their electrical properties and structure. The ion energy and fluence were within 0.2–40 keV and 10¹³–10¹⁵ cm⁻² respectively. The dc resistance enhances after the intensive ion beam treatment while the ac impedance decreases. Ti ion implantation with 40 keV energy and 10¹⁴ cm⁻² fluence induces decrease of the ac impedance by almost two orders of magnitude and appearance of the molecular hydrogen features in ¹H NMR spectrum. The UV–VIS spectra of the films are blue shifted after their exposal to the ion beams, which correlates with the presence of oxygen. The ratio of the oxygen to carbon peak intensities (O1s/C1s) in the XPS spectra is proposed as a measure for the local partial disturbance of the film. EPR spectra demonstrate formation of the paramagnetic states with g factor <2, which is accompanied with the down-field shift of the NMR spectrum. The ion beams are found to have no significant etching effect as per results of the film thickness measurements and AFM images.

Keywords: Ion implantation; rr-P3HT; Doping; Resistance; Ac impedance; Organic electronics

Erbium-ion implantation of single- and nano-crystalline ZnO

Cajzl, J.; Nekvindova, P.; Jeníčková, K.; Jagerová, A.; Malinský, P.; Remeš, Z.; Neykova, N.; Chang, Y.-Y.; Oswald, J.; Kentsch, U.; Macková, A.

This paper reports on the results of Er+ ion implantation into various ZnO structures - standard single crystal c-plane (0001) ZnO, nanostructured thin films and nanorods. Er+ ions were implanted using an ion implantation energy of 400 keV and implantation fluences in the range of 5×1014 to 5×1015 ions/cm2. Er concentration depth profiles and the degree of crystal damage were measured using Rutherford backscattering spectrometry (RBS) and RBS/channelling (RBS/C). Additionally, Raman spectroscopy was used to analyse structural modifications of the prepared samples. The main focus was placed on the luminescence properties of various ZnO structures. The results showed that the characteristic bands of ZnO, i.e. near-band-edge (NBE) luminescence and deep-level emission (DLE) - that can be influenced by the excitation wavelength - appeared in the spectra of single crystals and nanorods. The characteristic luminescence bands of erbium ions in the NIR region appeared in ZnO single-crystal samples and nano-crystalline films.

Keywords: ZnO; nanocrystalline thin films; nanorods; erbium; ion implantation; luminescence

Multi-direction channelling study of the Ag:YSZ nanocomposites prepared by ion implantation

Mikšová, R.; Jagerová, A.; Malinský, P.; Harcuba, P.; Veselý, J.; Holý, V.; Kentsch, U.; Macková, A.

The paper reports on implantation damage accumulation, Ag distribution and the interior morphology in different crystallographic orientations of implanted samples of cubic yttria-stabilised zirconia (YSZ). (100)-, (110)- and (111)-oriented YSZ was implanted with 400-keV Ag⁺ ions at ion fluences from 5 × 10¹⁴ to 5 × 10¹⁶ cm⁻². Rutherford backscattering spectrometry (RBS) in the channelling mode (RBS-C), as well as X-ray diffraction (XRD), were used for the quantitative measurement of the lattice disorder and Ag distribution. The defect propagation and Ag accumulation were observed using transmission electron microscopy (TEM) with the energy-dispersive X-ray spectroscopy (EDX). Although similar damage evolution trends were observed along with all channelling directions, the disorder accumulation is lower along the <110> direction than along the <100> and <111> direction. The damage extends much deeper than the theoretically predicted depths. It is attributed to long-range defect migration effects, confirmed by TEM. At the ion fluence of 5 × 10¹⁶ cm⁻², nanometre-sized Ag precipitates were identified in the depth of 30–130 nm based on the Ag concentration–depth profiles determined by RBS.

Keywords: Ag ion-implantation; Yttria-stabilized zirconia; Damage accumulation; Strain relaxation; Nanoparticles

Irradiation effects in monazite-(Ce) and zircon: Raman and photoluminescence study of Au-irradiated FIB foils

Nasdala, L.; Akhmadaliev, S.; Artac, A.; Chanmuang, N. C.; Habler, G.; Lenz, C.

Lamellae of 1.5 µm thickness, prepared from well-crystallised monazite-(Ce) and zircon samples using the focused-ion-beam technique, were subjected to triple irradiation with 1 MeV Au+ ions (15.6% of the respective total fluence), 4 MeV Au2+ ions (21.9%) and 10 MeV Au3+ ions (62.5%). Total irradiation fluences were varied in the range 4.5E12 -1.2E14 ions/cm2. The highest fluence resulted in amorphisation of both minerals; all other irradiations (i.e. up to 4.5E13 ions/cm2) resulted in moderate to severe damage. Lamellae were subjected to Raman and laser-induced photoluminescence analysis, in order to provide a means of quantifying irradiation effects using these two micro-spectroscopy techniques. Based on extensive Monte Carlo calculations and subsequent defect-density estimates, irradiation-induced spectroscopic changes are compared with those of naturally self-irradiated samples. The finding that ion irradiation of monazite-(Ce) may cause severe damage or even amorphisation, is in apparent contrast to the general observation that naturally self-irradiated monazite-(Ce) does not become metamict (i.e. irradiation-amorphised), in spite of high self-irradiation doses. This is predominantly assigned to the continuous low-temperature damage annealing undergone by this mineral; other possible causes are discussed. According to cautious estimates, monazite-(Ce) samples of Mesoproterozoic to Cretaceous ages have stored only about 1% of the total damage experienced. In contrast, damage in ion-irradiated and naturally self-irradiated zircon is on the same order; reasons for the observed slight differences are discussed. We may assess that in zircon, alpha decays create significantly less than 1000 Frenkel-type defect pairs per event, which is much lower than previous estimates. Amorphisation occurs at defect densities of about 0.10 dpa (displacements per lattice atom).

Keywords: Radiation damage; Heavy-ion irradiation; Focused ion beam; Raman spectroscopy; Photoluminescence


Ulrich Kentsch

Head Implanter
Phone: +49 351 260 3345