195 citations · 607 across the 18 of their papers we have counts for
15 papers · 1 filter
Giant Huang-Rhys Factor for Electron Capture by the Iodine Interstitial in Perovskite Solar Cells
Lucy D. Whalley, Puck van Gerwen, Jarvist M. Frost +3
Improvement in the optoelectronic performance of halide perovskite semiconductors requires the identification and suppression of non-radiative carrier trapping processes. The iodin…
Quick-start guide for first-principles modelling of point defects in crystalline materials
Sunghyun Kim, Samantha N. Hood, Ji-Sang Park +2
Defects influence the properties and functionality of all crystalline materials. For instance, point defects participate in electronic (e.g. carrier generation and recombination) a…
Comment on "Low-frequency lattice phonons in halide perovskites explain high defect tolerance toward electron-hole recombination"
Sunghyun Kim, Aron Walsh
Halide perovskites exhibit slow rates of non-radiative electron-hole recombination upon illumination. Chu et al. [Sci. Adv. 6 7, eaaw7453 (2020)] use the results of first-principle…
Anharmonic Lattice Relaxation during Non-radiative Carrier Capture
Sunghyun Kim, Samantha N. Hood, Aron Walsh
Lattice vibrations of point defects are essential for understanding non-radiative electron and hole capture in semiconductors as they govern properties including persistent photoco…
A Metal-Insulator Transition via Wigner Crystallization in Boron Triangular Kagome Lattice
Woo Hyun Han, Sunghyun Kim, In-Ho Lee +1
The flat band has attracted a lot of attention because it gives rise to many exotic phases, as recently demonstrated in magic angle twisted bilayer graphene. Here, based on first-p…
Open-Circuit Voltage Deficit in Cu2ZnSnS4 Solar Cells by Interface Band Gap Narrowing
Ji-Sang Park, Sunghyun Kim, Samantha N. Hood +1
There is evidence that interface recombination in Cu2ZnSnS4 solar cells contributes to the open-circuit voltage deficit. Our hybrid density functional theory calculations suggest t…
Lone-pair effect on carrier capture in CuZnSnS solar cells
Sunghyun Kim, Ji-Sang Park, Samantha N. Hood +1
The performance of kesterite thin-film solar cells is limited by a low open-circuit voltage due to defect-mediated electron-hole recombination. We calculate the non-radiative carri…
Stability and electronic properties of planar defects in quaternary I2-II-IV-VI4 semiconductors
Ji-Sang Park, Sunghyun Kim, Aron Walsh
Extended defects such as stacking faults and anti-site domain boundaries can perturb the band edges in CuZnSnS and CuZnSnSe, acting as a weak electron barrier or a…
Role of electron-phonon coupling and thermal expansion on band gaps, carrier mobility, and interfacial offsets in kesterite thin-film solar cells
Bartomeu Monserrat, Ji-Sang Park, Sunghyun Kim +1
The efficiencies of solar cells based on kesterite CuZnSnS (CZTS) and CuZnSnSe (CZTSe) are limited by a low open-circuit voltage due to high rates of non-radiative…
Opposing effects of stacking faults and antisite domain boundaries on the conduction band edge in kesterite quaternary semiconductors
Ji-Sang Park, Sunghyun Kim, Aron Walsh
We investigated stability and the electronic structure of extended defects including anti-site domain boundaries and stacking faults in the kesterite-structured semiconductors, Cu$…
A New Phosphorus Allotrope with Direct Band Gap and High Mobility
W. H. Han, Sunghyun Kim, In-Ho Lee +1
Based on ab initio evolutionary crystal structure search computation, we report a new phase of phosphorus called green phosphorus (λ-P), which exhibits the direct band gaps ranging…
Boron Triangular Kagome Lattice with Half-Metallic Ferromagnetism
Sunghyun Kim, W. H. Han, In-Ho Lee +1
Based on the first-principles evolutionary materials design, we report a stable boron Kagome lattice composed of triangles in triangles on a two-dimensional sheet. The Kagome latti…
Direct band gap carbon superlattices with efficient optical transition
Young Jun Oh, Sunghyun Kim, In-Ho Lee +2
We report pure carbon-based superlattices that exhibit direct band gaps and excellent optical absorption and emission properties at the threshold energy. The structures are nearly…
Dipole-Allowed Direct Band Gap Silicon Superlattices
Young Jun Oh, In-Ho Lee, Sunghyun Kim +2
Silicon is the most popular material used in electronic devices. However, its poor optical properties owing to its indirect band gap nature limit its usage in optoelectronic device…
A Finite-Size Supercell Correction Scheme for Charged Defects in One-Dimensional Systems
Sunghyun Kim, Ji-Sang Park, K. J. Chang
We propose a new finite-size correction scheme for the formation energy of charged defects and impurities in one-dimensional systems within density functional theory. The energy co…