51 citations · 285 across the 21 of their papers we have counts for
22 papers
Discrete Electron Emission
Arnar Jonsson, Kristinn Torfason, Andrei Manolescu +1
Analysis of space-charge effects on electron emission typically makes some assumption of continuity and smoothness, whether this is continuity of charge as in the classical derivat…
Impact of interface defects on the band alignment and performance of TiO/MAPI/CuO perovskite solar cells
Nicolae Filipoiu, Marina Cuzminschi, Mihaela Cosinschi +9
Optimizing the interfaces in perovskite solar cells (PSCs) is essential for enhancing their performance, improving their stability, and making them commercially viable for large-sc…
OH ions can reduce the iodide migration in MAPI
R. E. Brophy, M. Kateb, I. Ghitiu +6
One of the main degradation mechanisms of methylammonium lead iodine (MAPI), which is an important material for perovskite based solar cells, is the migration of iodide ions. It is…
Effect of pressure on the dynamics of iodine defects in MAPI: An atomistic simulation
Rachel Elizabeth Brophy, Movaffaq Kateb, Kristinn Torfason +4
The diffusion of iodine defects has been considered the most important degradation mechanism of methylammonium lead iodine (MAPI) in solar cells. The present study demonstrates the…
Simulation of short pulse photoemission in a micro-diode with implications for optimal beam brightness
Hákon Örn Árnason, Kristinn Torfason, Andrei Manolescu +1
Molecular dynamics simulations, with full Coulomb interaction are used to model short-pulse photoemission from a finite area in a microdiode. We demonstrate three emission regimes,…
Molecular Dynamics Simulations of Mutual Space-Charge Effect between Planar Field Emitters
Hakon Valur Haraldsson, Kristinn Torfason, Andrei Manolescu +1
Molecular dynamics simulations, with full Coulomb interaction and self-consistent field emission, are used to examine mutual space-charge interactions between beams originating fro…
Edge effect on the current-temperature characteristic of thermionic cathodes
Anna Sitek, Kristinn Torfason, Andrei Manolescu +1
We perform a computational study, based on the molecular dynamics method, of the shape of Miram curves obtained from microscale planar diodes. We discuss the smooth transition from…
Dynamics of a Field Emitted Beam from a Microscopic Inhomogeneous Cathode
Kristinn Torfason, Anna Sitek, Andrei Manolescu +1
We investigate by molecular dynamics simulations [arXiv:1412.4537 [physics.plasm-ph], arXiv:1608.06789 [physics.plasm-ph]] a beam of electrons released via field emission from a pl…
Space-Charge Limited Current from a Finite Emitter in Nano- and Microdiodes
Johannes Bergur Gunnarsson, Kristinn Torfason, Andrei Manolescu +1
We simulate numerically the classical charge dynamics in a microscopic, planar, vacuum diode with a finite emitter area and a finite number of electrons in the gap. We assume elect…
Space-charge effects in the field-assisted thermionic emission from nonuniform cathodes
Anna Sitek, Kristinn Torfason, Andrei Manolescu +1
We use computational simulations to study the electron emission and propagation in planar vacuum diodes. We show how space-charge affects thermionic emission from cathodes with two…
Controlled Coulomb effects in core-shell quantum rings
Anna Sitek, Miguel Urbaneja Torres, Kristinn Torfason +2
We analyse theoretically the possibilities of contactless control of in-gap states formed by a pair of electrons confined in a triangular quantum ring. The in-gap states are corner…
Normal and inverted hysteresis in perovskite solar cells
George Alexandru Nemnes, Cristina Besleaga, Viorica Stancu +6
Hysteretic effects are investigated in perovskite solar cells in the standard FTO/TiO/CHNHPbICl/spiro-OMeTAD/Au configuration. We report normal (NH) and inv…
Molecular Dynamics Simulations of Field Emission From a Prolate Spheroidal Tip
Kristinn Torfason, Agust Valfells, Andrei Manolescu
High resolution molecular dynamics simulations with full Coulomb interactions of electrons are used to investigate field emission from a prolate spheroidal tip. The space charge li…
Dynamic electrical behavior of halide perovskite based solar cells
George Alexandru Nemnes, Cristina Besleaga, Andrei Gabriel Tomulescu +4
A dynamic electrical model is introduced to investigate the hysteretic effects in the I-V characteristics of perovskite based solar cells. By making a simple ansatz for the polariz…
Terahertz pulsed photogenerated current in microdiodes at room temperature
Marjan Ilkov, Kristinn Torfason, Andrei Manolescu +1
Space-charge modulation of the current in a vacuum diode under photoemission leads to the formation of beamlets with time periodicity corresponding to THz frequencies. We investiga…
Molecular Dynamics Simulations of Field Emission From a Planar Nanodiode
Kristinn Torfason, Agust Valfells, Andrei Manolescu
High resolution molecular dynamics simulations with full Coulomb interactions of electrons are used to investigate field emission in planar nanodiodes. The effects of space charge…
Synchronization in arrays of vacuum microdiodes
Marjan Ilkov, Kristinn Torfason, Andrei Manolescu +1
Simulations have shown that space-charge effects can lead to regular modulation of photoemitted beams in vacuum diodes with gap sizes on the order of 1 micron and accelerating volt…
Thermoelectric Current and Coulomb-Blockade Plateaus in a Quantum Dot
Kristinn Torfason, Andrei Manolescu, Sigurdur I. Erlingsson +1
A Generalized Master Equation (GME) is used to study the thermoelectric currents through a quantum dot in both the transient and steady-state regime. The two semi-infinite leads ar…
Excitation of collective modes in a quantum flute
Kristinn Torfason, Andrei Manolescu, Valeriu Molodoveanu +1
We use a generalized master equation (GME) formalism to describe the non-equilibrium time-dependent transport of Coulomb interacting electrons through a short quantum wire connecte…
Generalized Master equation approach to mesoscopic time-dependent transport
Kristinn Torfason, Andrei Manolescu, Valeriu Molodoveanu +1
We use a generalized Master equation (GME) formalism to describe the non-equilibrium time-dependent transport through a short quantum wire connected to semi-infinite biased leads.…
Magnetotransport in a time-modulated double quantum point contact system
Chi-Shung Tang, Kristinn Torfason, Vidar Gudmundsson
We report on a time-dependent Lippmann-Schwinger scattering theory that allows us to study the transport spectroscopy in a time-modulated double quantum point contact system in the…
Coherent magnetotransport and time-dependent transport through split-gated quantum constrictions
Kristinn Torfason, Chi-Shung Tang, Vidar Gudmundsson
The authors report on modeling of transport spectroscopy in split-gate controlled quantum constrictions. A mixed momentum-coordinate representation is employed to solve a set of ti…