Inst. Hochfrequenz- und Halbleiter-Systemtechnologien

141 Items

Recent Submissions
Back- and front-side texturing for light-management in perovskite / silicon-heterojunction tandem solar cells

Jošt, Matej ; Albrecht, Steve ; Lipovšek, Benjamin ; Krč, Janez ; Korte, Lars ; Rech, Bernd ; Topič, Marko (2016-12)

The perovskite / silicon-heterojunction (SHJ) tandem solar cell can theoretically overcome the efficiencies of the single junction solar cells with experimental results not far behind. Here, we use optical simulations to analyze the potential of such currently feasible monolithic perovskite / SHJ tandem devices. We consider three different device designs in the optical simulations: planar devic...

Optical interactions for internal signal tracking in ICs

Vogt, Ivo (2018)

This work investigates and improves two common techniques of electronics failure analysis, (spectral) photon emission microscopy (PEM/SPEM) and electro-optical frequency mapping (EOFM). The scientific focus is set on the physical interaction between light and an active semiconductor device. Investigated test structures include 14-40nm FinFETs of several technology generations, as well as planar...

Polycrystalline silicon solar cells on glass - toward an industry compatible process

Frijnts, Tim Robin (2018)

Multicrystalline silicon wafer based solar cells are currently the dominating photovoltaic technology. Liquid phase crystallized, thin film, polycrystalline silicon on glass (LPC-Si) is a promising approach to reduce the cost of crystalline silicon solar cells. In this thesis the large area plasma enhanced chemical vapour deposition (PECVD) of SiOx/SiNx/SiOxNy interlayers and 5-15 µm amorphous...

Device simulation of high-performance SiGe heterojunction bipolar transistors

Korn, Julian (2018)

Silicon-germanium (SiGe) heterojunction bipolar transistors (HBT) are well suited for high-frequency applications. Their performance has been improved continuously in recent years. Today's SiGe HBT technologies show transit frequencies fT up to 300 GHz and maximum oscillation frequencies up to 500 GHz. Numerical device simulation plays an important role in the development of SiGe HBTs. Possible...

Analysis of photonic crystals for interaction with near-surface emitters

Barth, Carlo (2018)

The tailorable optical properties of photonic crystals enable a broad spectrum of applications beyond just the photonic bandgap. Leaky modes of photonic crystal slabs which couple to the external light field can facilitate light extraction from emitters located inside the slab or near the surface, known as the enhanced extraction effect. This effect can enhance light-emitting diodes or the outp...

Insights into the reversibility of aluminum graphite batteries

Elia, Giuseppe Antonio ; Hasa, Ivana ; Greco, Giorgia ; Diemant, Thomas ; Marquardt, Krystan ; Hoeppner, Katrin ; Behm, R. Jürgen ; Hoell, Armin ; Passerini, Stefano ; Hahn, Robert (2017)

Herein we report a novel study on the reaction mechanism of non-aqueous aluminum/graphite cell chemistry employing 1-ethyl-3-methylimidazolium chloride:aluminum trichloride (EMIMCl:AlCl3) as the electrolyte. This work highlights new insights into the reversibility of the anion intercalation chemistry besides confirming its outstanding cycle life exceeding 2000 cycles, corresponding to more than...

The Influence of ITO Dopant Density on J-V Characteristics of Silicon Heterojunction Solar Cells: Experiments and Simulations

Kirner, Simon ; Hartig, Manuel ; Mazzarella, Luana ; Korte, Lars ; Frijnts, Tim ; Scherg-Kurmes, Harald ; Ring, Sven ; Stannowski, Bernd ; Rech, Bernd ; Schlatmann, Rutger (2015)

The TCO/a-Si:H(p) contact is a critical part of the silicon heterojunction solar cell. At this point, holes from the emitter have to recombine loss free with electrons from the TCO. Since tunneling is believed to be the dominant transport mechanism, a high dopant density in both adjacent layers is critical. In contrast to this, it has been reported that high TCO dopant density can reduce field ...

Front-side interface engineering for liquid-phase crystallized silicon solar cells on glass

Preissler, Natalie (2018)

Liquid-phase crystallization (LPC) is a process technology to fabricate thin (< 30 μm) crystalline silicon layers on glass substrates. To this end, as-deposited amorphous or nano-crystalline silicon layers on glass are molten locally with a high energy density source (laser or electron beam). Subsequently, the silicon cools down and crystallizes. Resulting layers exhibit grains with a length of...

24 GHz low-power switch-channel CMOS transceiver for wireless localization

Zhang, Tao ; Hamidian, Amin ; Shu, Ran ; Subramanian, Viswanathan (2014)

A 24 GHz low-power transceiver is designed, fabricated, and characterized using 130 nm complementary metal-oxide semiconductor (CMOS) process. The designed transceiver is targeted for frequency-modulated-continuous-wave (FMCW) wireless local positioning. The transceiver includes four switchable receiving channels, one transmitting channel and local-oscillator generation circuitries. Several pow...

Evaluation of GaN-HEMT power amplifiers using BST-based components for load modulation

Arnous, Mhd. Tareq ; Wiens, Alex ; Saad, Paul ; Preis, Sebastian ; Zhang, Zihui ; Jakoby, Rolf ; Böck, Georg (2014)

In this paper, the concept of load-modulated power amplifiers (PAs) is studied. Two GaN-HEMT power amplifiers (PAs), targeted for high efficiency at maximum and output back-off (OBO) power levels, are designed, implemented, and tested across 1.8–2.2 GHz. The load modulation in the first design is realized by tuning the shunt capacitors in the output matching network. A novel method is employed ...

Design and analysis of 80-W wideband asymmetrical Doherty amplifier

Bathich, Khaled ; Böck, Georg (2014)

This paper presents the analysis and design of a wideband asymmetrical Doherty amplifier. The frequency response of the output combining network of the Doherty amplifier with arbitrary back-off level configuration is analyzed. Other bandwidth-limiting factors were discussed and analyzed as well. A number of performance enhancement techniques were taken into consideration to obtain high and flat...

A 60 GHz fully differential LNA in 90 nm CMOS technology

Malignaggi, Andrea ; Hamidian, Amin ; Böck, Georg (2013)

The present paper presents a fully differential 60 GHz four stages low-noise amplifier for wireless applications. The amplifier has been optimized for low-noise, high-gain, and low-power consumption, and implemented in a 90 nm low-power CMOS technology. Matching and common-mode rejection networks have been realized using shielded coplanar transmission lines. The amplifier achieves a peak small-...

Efficient technique for ultra broadband, linear power amplifier design

Sayed, Ahmed ; Preis, Sebastian ; Böck, Georg (2012)

In this paper, a 10 W ultra-broadband GaN power amplifier (PA) is designed, fabricated, and tested. The suggested design technique provides a more accurate starting point for matching network synthesis and better prediction of achievable circuit performance. A negative-image model was used to fit the extracted optimum impedances based on source-/load-pull technique and multi-section impedance m...

Future recycling flows of tellurium from cadmium telluride photovoltaic waste

Marwede, Max ; Reller, Armin (2012)

According to the European Photovoltaic Industry Association, photovoltaic energy has the potential to contribute up to 13% to the global electricity supply by 2040. A part of this electricity production will come from thin-film photovoltaic technologies. From various thin-film technologies available on the market today, low-cost cadmium telluride photovoltaics (CdTe-PV) can be considered the ma...

Four wave mixing at 1550 nm in silicon waveguides

Gajda, Andrzej (2017)

Traffic in data communication networks has seen continuous growth over many decades. Taking the example of transport networks we observe a growth rate of about 60% per year in capacity. The increase in traffic is supported by various technologies but mainly driven by applications related to social media, moving images, internet of things etc. An important contender for future increase of fiber ...

Micro-integrated diode laser modules for quantum optical sensors in space

Kohfeldt, Anja (2017)

Quantum sensors are rely on laser technology for preparation and for manipulation of their quantum probes. With the endeavour of operating quantum sensors in micro-gravity in order to gain measurement precision, laser technology has to be developed further to meet the new requirements. In addition to high frequency stability at specific wavelengths and sufficient optical output power, the laser...

Performance analysis of low jitter high-speed photonic analog-to-digital converters in silicon photonics

Krune, Edgar (2017)

The performance of electronic analog-to-digital converters (ADCs) is mainly limited by the sampling instant precision if high-frequency signals are sampled. Its uncertainty is called timing jitter. The electrical clock generation and its distribution on chip are limited to a jitter of 100 fs and no significant improvement was achieved in the last decade. Physical restrictions prevent its furthe...

On-chip automation of cell-free protein synthesis: new opportunities due to a novel reaction mode

Georgi, V. ; Georgi, Leopold ; Blechert, Martin ; Bergmeister, Merlin ; Zwanzig, Michael ; Wüstenhagen, Doreen A. ; Bier, Frank F. ; Jung, Erik ; Kubick, Stefan (2016)

Many pharmaceuticals are proteins or their development is based on proteins. Cell-free protein synthesis (CFPS) is an innovative alternative to conventional cell based systems which enables the production of proteins with complex and even new characteristics. However, the short lifetime, low protein production and expensive reagent costs are still limitations of CFPS. Novel automated microfluid...

Exceptional long-life performance of lithium-ion batteries using ionic liquid-based electrolytes

Elia, Giuseppe Antonio ; Ulissi, Ulderico ; Jeong, Sangsik ; Passerini, Stefano ; Hassoun, Jusef (2016)

Advanced ionic liquid-based electrolytes are herein characterized for application in high performance lithium-ion batteries. The electrolytes based on either N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imide (Pyr(14)TFSI), N-butyl-N-methylpyrrolidinium bis(fluoro-sulfonyl) imide (Pyr(14)FSI), N-methoxy-ethyl-N-methylpyrrolidinium bis(trifluoromethane-sulfonyl) imide (Pyr(12O1)TF...

Fabrication and characterization of nanotextures for light management in photovoltaic and optoelectronic devices

Jošt, Marko (2017)

Light management is an important aspect of photovoltaics to assure efficient exploitation of solar energy and improve the efficiency of solar cells. Efficient light management is based on anti-reflection and light scattering. The former results in increased light in-coupling, and the latter prolongs the optical path in the active layer of a solar cell; consequently, the conversion efficiency in...