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Search Publications by: Paul M Haney (Fed)

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Displaying 26 - 50 of 75

Sesame: A Numerical Simulation Tool for Polycrystalline Photovoltaics

June 11, 2018
Author(s)
Benoit H. Gaury, Yubo Sun, Peter Bermel, Paul M. Haney
We present a new software simulation tool "Sesame", which solves the drift-diffusion-Poisson equations in 1 and 2-dimensions. Sesame is distributed both as an open source Python package and as a standalone executable for Windows. The software is designed

Nanoscale photocurrent mapping in perovskite solar cells

June 1, 2018
Author(s)
Yohan Yoon, Dongheon Ha, Ik Jae Park, Paul M. Haney, Sangwook Lee, Nikolai Zhitenev
In this work, we study spatially-resolved generation of photocurrent of methylammonium lead iodide (CH3NH3PbI3) perovskite solar cells to reveal the microscopic effects of annealing temperature and degradation under light exposure. Correlating a novel

Thermally driven anomalous Hall effect transitions in FeRh

April 30, 2018
Author(s)
Adrian Popescu, Pablo Rodrigues-Lopez, Paul M. Haney, Lilia M. Woods
Materials exhibiting controllable magnetic phase transitions are currently in demand for many spintronics applications. Here we investigate from first principles the electronic structure and intrinsic anomalous Hall, spin Hall and anomalous Nernst response

From Microparticles to Nanowires and Back: Radical Transformations in Plated Li Metal Morphology Revealed via in situ scanning electron microscopy

February 3, 2018
Author(s)
Alexander Yulaev, Vladimir P. Oleshko, Paul M. Haney, Jialin Liu, Yue Qi, Talin Alec, Leite Marina, Andrei A. Kolmakov
Li metal is the preferred anode material for all-solid-state Li batteries due to its high theoretical capacity and low voltage vs. standard hydrogen electrode. However, stable plating and stripping of Li metal in contact with a solid electrolyte at high

Optical spin transfer and spin-orbit torques in thin-film ferromagnets

August 30, 2017
Author(s)
Junwen Li, Paul M. Haney
We study the optically induced torques on thin film ferromagnetic layers under excitation by circularly polarized light. We include Rashba spin-orbit coupling and assume an out-of-plane magnetization, and consider incident light with an in-plane component

Analytic description of the impact of grain boundaries on Voc

June 26, 2017
Author(s)
Paul M. Haney, Benoit H. Gaury
The impact of grain boundaries on the performance of polycrsytalline photovoltaics remains an open question. We present a simplified description of dark grain boundary recombination current. The dark current takes the form of a diode equation, and the

Deconvoluting the Influences of 3D Structure on the Performance of Photoelectrodes for Solar-Driven Water Splitting

February 7, 2017
Author(s)
Daniel V. Esposito, Youngmin Lee, Heayoung Yoon, Paul M. Haney, Natalie Labrador, Thomas P. Moffat, A. A. Talin, Veronika A. Szalai
Abstract Three-dimensionally (3D) structured photoelectrodes offer a number of potential benefits for solar fuels production compared to conventional planar photoelectrodes, including decreased optical losses, higher surface area for catalysis, more facile

Circular Photogalvanic Effect in Organometal Halide Perovskite CH3NH3PbI3

November 7, 2016
Author(s)
Junwen Li, Paul M. Haney
We study the circular photogalvanic effect in the organometal halide perovskite solar cell absorber CH$_3$NH$_3$PbI$_3$. The calculated photocurrent density is about $10^{-9}$ A/W, comparable to the previously studied quantum well and bulk Rashba systems

Depletion region surface effects in electron beam induced current measurements

September 7, 2016
Author(s)
Paul M. Haney, Heayoung Yoon, Benoit H. Gaury, Nikolai B. Zhitenev
Electron beam induced current (EBIC) is a powerful characterization technique which offers the high spatial resolution needed to study polycrystalline solar cells. Ideally, an EBIC measurement reflects the spatially resolved quantum efficiency of the

Antiferromagnetic domain wall motion driven by spin-orbit torques

August 16, 2016
Author(s)
Takayuki Shiino, Se-Hyeok Oh, Paul M. Haney, Seo-Won Lee, Gyungchoon Go, Byong-Guk Park, Kyung-Jin Lee
We theoretically investigate dynamics of antiferromagnetic domain walls driven by spin-orbit torques in antiferromagnet/heavy metal bilayers. We show that spin-orbit torques drive antiferromagnetic domain walls much faster than ferromagnetic domain walls

Interfacial magnetic anisotropy from a 3-dimensional Rashba substrate

July 18, 2016
Author(s)
Junwen Li, Paul M. Haney
We study the magnetic anisotropy which arises at the interface between a thin film ferromagnet and a 3-d Rashba material. The 3-d Rashba material is characterized by the spin-orbit strength $\alpha$ and the direction of broken bulk inversion symmetry $\hat

Minority-carrier dynamics in semiconductors probed by two-photon microscopy

May 31, 2016
Author(s)
Benoit H. Gaury, Paul M. Haney
Two-photon time-resolved photoluminescence has been recently applied to various semiconductor devices to determine carrier lifetime and surface recombination velocities. So far the theoretical modeling activity has been mainly limited to the commonly used

k-asymmetric spin-splitting at the interface between transition metal ferromagnets and heavy metals.

May 23, 2016
Author(s)
Sergiy Grytsyuk, Abderrezak Belabbes, Paul M. Haney, Hyun-Woo Lee, Kyung Jin Lee, Mark D. Stiles, Udo Schwingenschlogl, Aurelien Manchon
We systematically investigate the spin-orbit coupling-induced band splitting originating from inversion symmetry breaking at the interface between a Co monolayer and 4d (Tc, Ru, Rh, Pd, and Ag) or 5d (Re, Os, Ir, Pt, and Au) transition metals. In spite of

Optical Spintronics in Organic-Inorganic Perovskites Photovoltaics

April 25, 2016
Author(s)
Junwen Li, Paul M. Haney
Organic-inorganic halide CH 3NH 3PbI 3 solar cells have attracted enormous attention in recent years due to their remarkable power conversion efficiency. These materials should exhibit interesting spin-dependent properties as well, owing to the strong spin

Local photocarrier dynamics in CdTe solar cells under optical and electron beam excitations

December 16, 2015
Author(s)
Heayoung Yoon, Paul M. Haney, Yohan Yoon, Sang M. An, James I. Basham, Nikolai Zhitenev
We investigate local carrier dynamics in n-CdS / p-CdTe solar cells, where the electron-hole pairs are generated by either near-field optical illumination or highly focused electron beam excitation. A focused ion milling process was used to prepare a