SC07–Interpretation of a capacitance in polycrystalline solar cells: time domain simulations

Wisniewski K.

In this work, we presented simulations of capacitance of polycrystalline solar cells using time-dependent calculations based on the finite element method. Our starting point was capacitance transient measurements of thin-film CIGS solar cells, which to this day, after twenty years of investigations, do not have the correct theoretical description. We showed, that there exists a […]

LD11–Influence of Coulomb Scattering on the Coupling between Longitudinal Modes in Nitride Laser Diodes

Kuhn E., Uhlig L., Wachs M., Schwarz U.T., Thränhardt A.

Due to their small separation of longitudinal modes, Fabry-Perot type laser diodes show rich mode competition effects. For example streak camera measurements show cyclic mode hopping, where the currently active longitudinal mode changes from lower to higher wavelengths. This effect can be explained by beating vibrations of the carrier densities in the quantum wells and […]

NM04–Atomistic analysis of band-to-band tunnelling in direct-gap GeSn group-IV alloys

Dunne M. D., Broderick C. A., Luisier M., O’Reilly E. P.

The emergence of a direct band gap in Ge1-xSnx alloys has stimulated interest in developing Ge1-xSnx alloys and nanostructures for applications in Si-compatible electronic and photonic devices. The direct band gap of Ge1-xSnx, combined with the strong band gap reduction associated with Sn incorporation, makes Ge1-xSnx a promising material system for the development of Si-compatible […]

MM05–Project Skeletons for Scientific Software

Riesch M., Haider M., Jirauschek C.

Although research relies heavily on software packages such as mathematical libraries or data analysis tools, efforts to provide high-quality scientific software are hardly rewarded. As a possible way out of this dilemma, project skeletons can be employed to accelerate software development while ensuring code quality. In this work, we review existing project skeletons and present […]

LD07–Thermal Characterization of the Birefringence of Nematic Liquid Crystals for the Design of Widely-tunable LC-VCSELs

Simaz A., Boisnard B., Camps T., Doucet J. B., Reig B., Tibaldi A., Debernardi P., Bardinal V.

In this work, the thermo-optical properties of nematic liquid crystals are investigated through localized reflectance spectra measurements performed on a tunable LC-filter. The final aim is to insert such LC in the cavity of a tunable VCSEL device, in which local self-heating due to optical or electrical pumping must be taken into account. We demonstrate […]

SC08–The lateral photovoltage scanning method (LPS): Understanding doping variations in silicon crystals

Kayser S., Rotundo N., Fuhrmann J., Dropka N., Farrell P.

The lateral photovoltage scanning method (LPS) can be used to detect undesired impurities which appear in silicon crystals during growth. Our goal is to make a digital twin of the LPS method. To this end, we replace inflexible blackbox code with a physics preserving finite volume discretization, confirming three theoretical results via a new simulation […]

LD12–Modeling Impact of Oxide Island on the Lasing of ARROW-VCSEL

Dems M., Wieckowska M.

We analyze the impact of a low-refractive antiresonant oxide island buried in a top VCSEL mirror on the lasing conditions of lateral modes of different orders. By performing comprehensive thermal, electrical, and optical numerical analysis of the VCSEL device, we show the impact of the size and location of the oxide island on the current […]

NM05–Simulation of electro optic modulators based on plasmonic directional couplers

Ghomashi M., Tibaldi A., Bertazzi F., Vallone M., Goano M., Ghione G.

In this paper, a new concept and geometry are proposed for plasmonic modulators, whose operation is based on the coupling between two plasmonic slots. An electro-optic polymer is exploited as an active material, and the device can be implemented within a Silicon Photonics platform. The device operates at 1550nm wavelength, typical of data center or […]

MM04–Completely Positive Trace Preserving Methods for the Lindblad Equation

Riesch M., Pikl A., Jirauschek C.

The Lindblad master equation is a valuable tool in quantum mechanics, which describes the dynamics of open systems. In the scope of our research, it is combined with the one-dimensional Maxwell’s equations to form the generalized Maxwell-Bloch equations. Since analytical solutions are not available in the general case, numerical methods have to be employed to […]