Publications de Patrik Willi Hoffmann

High-quality epitaxial BaTiO3 films grown by high-vacuum chemical vapor deposition for integrated electro-optical devices

Synthesizing high-quality epitaxial BaTiO3 (BTO) by means of high-vacuum chemical vapor deposition (HV-CVD) requires a precise control over precursor fluxes impinging onto the heated substrate surface so that the incorporation rates of all elements corresp ...

2025

Electron beam-based direct writing of nanostructures using a palladium β-ketoesterate complex

Patrik Willi Hoffmann

Gas-assisted focused electron beam-induced deposition (FEBID) as a direct, minimally invasive 3D nanopatterning tool offers many advantages in making nanostructures with complex shapes and novel compositions for evolving nanotechnological applications. In ...

BEILSTEIN-INSTITUT2025

Unsupervised quality monitoring of metal additive manufacturing using Bayesian adaptive resonance

Patrik Willi Hoffmann

Metal additive manufacturing is a recent breakthrough technology that promises automated production of complex geometric shapes at low operating costs. However, its potential is not yet fully exploited due to the low reproducibility of quality in mass prod ...

CELL PRESS2024

Photonic methods for rapid crystallization of LiMn2O4 cathodes for solid-state thin-film batteries

Patrik Willi Hoffmann

High temperature and prolonged thermal annealing for the crystallization of cathode in thin-film batteries (TFBs) restricts the choice of current collector and substrates and causes lithium loss in the cathode. This work explores photonic-based alternative ...

2021

Nanosecond pulsed laser-processing of CVD diamond

Patrik Willi Hoffmann, Marco Cantoni, Sébastien Equis

This work considers the resulting material structural effects of laser-processing chemical vapor deposited (CVD) diamond. The utilized 532 nm wavelength laser had a pulse duration of 40 ns together with a spot diameter of ca. 40 mu m. The effect of cutting ...

ELSEVIER SCI LTD2020

Impact of oxygen content in powders on the morphology of the laser molten tracks in preparation for additive manufacturing of silicon

Patrik Willi Hoffmann, Lucas Güniat, Marc Leparoux

Powder additive pulsed Nd:YAG laser (wavelength 1064 nm), with the aim of preparing AM of such material. The influence of oxygen content in the initial silicon powders on the continuous tracks morphology was investigated. It was found that the initial oxyg ...

ELSEVIER2020

Length Microstructure analysis of epitaxial BaTiO3 thin films on SrTiO3-buffered Si: Strain and dislocation density quantification using HRXRD methods

Patrik Willi Hoffmann

Barium titanate (BTO) is a promising perovskite-like material, exhibiting interesting functionalities, such as ferroelectricity, piezoelectricity, high dielectric constant, and electrooptic coefficients. All these properties are closely related to the orie ...

2020

Microfabrication of curved sidewall grooves using scanning nanosecond excimer laser ablation

Patrik Willi Hoffmann, André Gabriel Kostro, Josef Andreas Schuler, Georgios Violakis, Jing Gong

Novel glazing with embedded micro-mirrors can significantly reduce the energy consumption due to cooling and lighting in buildings. Especially promising are large arrays of periodic micro compound-parabolic-concentrators (CPCs) with angular-selected transm ...

SPIE2018

The Serotonin receptor 3E subunit variant HTR3E c.*76G> A is confirmed as a risk factor for IBS-D in females

Patrik Willi Hoffmann, Christian Hammer

WILEY2018

Microstructure and ferroelectricity of BaTiO3 thin films on Si for integrated photonics

Patrik Willi Hoffmann, Michael Oliver Reinke, Chiara Marchiori

Significant progress has been made in integrating novel materials into silicon photonic structures in order to extend the functionality of photonic circuits. One of these promising optical materials is BaTiO3 or barium titanate (BTO) that exhibits a very l ...

Institute of Physics2017

Surface Reaction Kinetics of Titanium Isopropoxide and Water in Atomic Layer Deposition

Patrik Willi Hoffmann, Yury Kuzminykh, Michael Oliver Reinke

In atomic layer deposition processes (ALD), surface reactions of adsorbed precursor species lead to the formation of thin films. In order to achieve a well-controlled, self-limiting process, the substrate is sequentially exposed to different precursor mole ...

American Chemical Society2016

Surface 3D Micro Free Forms: Multifunctional Microstructured Mesoporous alpha-Alumina by in Situ Slip Casting Using Excimer Laser Ablated Polycarbonate Molds

Paul Bowen, Patrik Willi Hoffmann, Sriharitha Rowthu

Ceramic surface microstructuring is a rapidly growing field with a variety of applications in tribology, wetting, biology, and so on. However, there are limitations to large-area microstructuring and fabrication of three-dimensional (3D) micro free forms. ...

Amer Chemical Soc2015

Combinatorial HV-CVD survey of barium triisopropyl cyclopentadienyl and titanium tetraisopropoxide for the deposition of BaTiO3

Patrik Willi Hoffmann, Yury Kuzminykh, Michael Oliver Reinke

Barium titanate is a very promising material for the integration of optical communication into electronic integrated circuits. For a successful integration into CMOS compatible technology, a growth process has to be found which allows forming crystalline B ...

Wiley-VCH Verlag2015

Low Temperature Chemical Vapor Deposition Using Atomic Layer Deposition Chemistry

Patrik Willi Hoffmann, Yury Kuzminykh, Michael Oliver Reinke

Chemical vapor deposition (CVD) techniques rely on high temperatures to activate the chemical decomposition of precursors on the substrate surface. Lower temperatures are applied in atomic layer deposition (ALD), where deliberate pyrolysis of the precursor ...

American Chemical Society2015

Selective Growth of Titanium Dioxide by Low-Temperature Chemical Vapor Deposition

Patrik Willi Hoffmann, Yury Kuzminykh, Michael Oliver Reinke

A key factor in engineering integrated optical devices such as electro-optic switches or waveguides is the patterning of thin films into specific geometries. In particular for functional oxides, etching processes are usually developed to a much lower exten ...

Amer Chemical Soc2015

Limitations of patterning thin films by shadow mask high vacuum chemical vapor deposition

Patrik Willi Hoffmann, Yury Kuzminykh, Michael Oliver Reinke

A key factor in engineering integrated devices such as electro-optic switches or waveguides is the patterning of high quality crystalline thin films into specific geometries. In this contribution high vacuum chemical vapor deposition (HV-CVD) was employed ...

Elsevier2014

Evaluation of niobium dimethylamino-ethoxide for chemical vapour deposition of niobium oxide thin films

Patrik Willi Hoffmann, Estelle Wagner, Giacomo Benvenuti, Ali Dabirian, Yury Kuzminykh

Chemical vapour deposition (CVD) processes depend on the availability of suitable precursors. Precursors that deliver a stable vapour pressure are favourable in classical CVD processes, as they ensure process reproducibility. In high vacuum CVD (HV-CVD) pr ...

Elsevier2014

Precursor adsorption efficiency of titanium tetra isopropoxide in the presence of a barium beta-diketonate precursor

Patrik Willi Hoffmann, Yury Kuzminykh, Michael Oliver Reinke

Barium titanate is a promising candidate for integrated photonic application due to its high electro-optic coefficient; therefore the need arises for a suitable deposition technique which provides high film quality at low temperatures (below 500 degrees C) ...

Elsevier Science Sa2013

High vacuum chemical vapour deposition of oxides: A review of technique development and precursor selection

Patrik Willi Hoffmann, Ali Dabirian, Yury Kuzminykh, Michael Oliver Reinke

Thin films of oxide materials are widely used for various types of applications. The selection of an appropriate deposition method depends on the aimed material and application. We review here a high vacuum chemical vapour deposition (HV-CVD) method, which ...

Elsevier2013

Hierarchical positioning of gold nanoparticles into periodic arrays using block copolymer nanoring templates

Patrik Willi Hoffmann, Harry Heinzelmann, Raphaël Pugin, Li Wang, Franck Montagne

We report a simple and versatile self-assembly method for controlling the placement of functional gold nanoparticles on silicon substrates using micellar templates. The hierarchical positioning of gold nanoparticles is achieved in one-step during the spont ...

2011