Publications de Hobeom Kim | EPFL Graph Search

Ultra-uniform perovskite crystals formed in the presence of tetrabutylammonium bistriflimide afford efficient and stable perovskite solar cells

Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Zhaofu Fei, Hiroyuki Kanda, Hobeom Kim, Yong Ding, Jianxing Xia, Alwani Imanah Rafieh, Jaekeun Lim

Compositional engineering of organic-inorganic metal halide perovskite allows for improved optoelectrical properties, however, phase segregation occurs during crystal nucleation and limits perovskite solar cell device performance. Herein, we show that by a ...

2024

Shallow-level defect passivation by 6H perovskite polytype for highly efficient and stable perovskite solar cells

Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Farzaneh Fadaei Tirani, Pascal Alexander Schouwink, Hiroyuki Kanda, Hobeom Kim, So-Min Yoo, Yong Ding

The power conversion efficiency of perovskite solar cells continues to increase. However, defects in perovskite materials are detrimental to their carrier dynamics and structural stability, ultimately limiting the photovoltaic characteristics and stability ...

Nature Research2024

Photonic nanostructures mimicking floral epidermis for perovskite solar cells

Mohammad Khaja Nazeeruddin, Hobeom Kim

Here, we report photonic nanostructures replicated from the adaxial epidermis of flower petals onto light-polymerized coatings using low-cost nanoimprint lithography at ambient temperature. These multifunctional nanocoatings are applied to confer enhanced ...

ELSEVIER2022

Employing 2D-Perovskite as an Electron Blocking Layer in Highly Efficient (18.5%) Perovskite Solar Cells with Printable Low Temperature Carbon Electrode

Mohammad Khaja Nazeeruddin, Dmitry Bogachuk, Hiroyuki Kanda, Hobeom Kim, So-Min Yoo, Jaekeun Lim

Interface engineering and passivating contacts are key enablers to reach the highest efficiencies in photovoltaic devices. While printed carbon-graphite back electrodes for hole-transporting material (HTM)-free perovskite solar cells (PSCs) are appealing f ...

WILEY-V C H VERLAG GMBH2022

Strain effects on halide perovskite solar cells

Mohammad Khaja Nazeeruddin, Ulf Anders Hagfeldt, Hobeom Kim, Bowen Yang, Jiajia Suo

Halide perovskite solar cells (PSCs) have achieved power conversion efficiencies (PCEs) approaching 26%, however, the stability issue hinders their commercialization. Due to the soft ionic nature of perovskite materials, the strain effect on perovskite fil ...

Royal Society of Chemistry2022

Asymmetrically Substituted 10H,10 ' H-9,9 '-Spirobi[acridine] Derivatives as Hole-Transporting Materials for Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Yi Zhang, Hiroyuki Kanda, Nadja Isabelle Desiree Klipfel, Hobeom Kim, Bin Ding, Jianxing Xia

Hole-transporting materials (HTMs) based on the 10H, 10 ' H-9,9 '-spirobi [acridine] core (BSA50 and BSA51) were synthesized, and their electronic properties were explored. Experimental and theoretical studies show that the presence of rigid 3,6-dimethoxy- ...

Wiley-VCH Verlag GmbH2022

Superhalogen Passivation for Efficient and Stable Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Hobeom Kim

Metal-halide perovskites are optoelectronic materials applied to solar cells as a light absorber due to their excellent optoelectronic properties. The power conversion efficiency of perovskite solar cells (PSCs) reaches 25.7% certified, which stands in com ...

WILEY-V C H VERLAG GMBH2022

Phase-Pure Quasi-2D Perovskite by Protonation of Neutral Amine

Mohammad Khaja Nazeeruddin, Marc Dessimoz, Hiroyuki Kanda, Cansu Igci, Hobeom Kim, So-Min Yoo

Phase control of low-dimensional metal-halide perovskites (LDPs) greatly affects their optoelectronic properties, and phase-pure LDPs are desirable to achieve efficient perovskite optoelectronic devices such as solar cells and light-emitting diodes. Herein ...

AMER CHEMICAL SOC2021

Piezo-electric and -phototronic effects of perovskite 2D|3D heterostructures

Mohammad Khaja Nazeeruddin, Hobeom Kim

Dimensionally-engineered perovskite heterostructures are highly attractive, as recently shown to be useful for enhancing the stability and efficiency in perovskite solar cells. Here, we first report piezo-electric and -phototronic effects found in two-dime ...

Elsevier2021

Advances in solution-processed near-infrared light-emitting diodes

Mohammad Khaja Nazeeruddin, Hobeom Kim

A summary of recent advances in the near-infrared light-emitting diodes that are fabricated by solution-processed means, with coverage of devices based on organic semiconductors, halide perovskites and colloidal quantum dots. ...

Nature Publishing Group2021

Highly Planar Benzodipyrrole-Based Hole Transporting Materials with Passivation Effect for Efficient Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Mounir Driss Mensi, Hiroyuki Kanda, Cansu Igci, Albertus Adrian Sutanto, Hobeom Kim

Three benzodipyrrole (BDP)-based organic small molecules with substituted 4-methoxyphenyl (CB-1), 3-fluorophenyl (CB-2), and 3-trifluoromethylphenyl (CB-3) are designed, synthesized, and used as a hole-transporting material (HTM) for perovskite solar cells ...

WILEY-V C H VERLAG GMBH2021

Phosphine Oxide Derivative as a Passivating Agent to Enhance the Performance of Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Mounir Driss Mensi, Valentin Ianis Emmanuel Queloz, Tom Theodorus Antonius Lummen, Aditya Gilra, Aron Joel Huckaba, Hiroyuki Kanda, Cansu Igci, Albertus Adrian Sutanto, Hobeom Kim

Defects of metal-halide perovskites detrimentally influence the optoelectronic properties of the thin film and, ultimately, the photovoltaic performance of perovskite solar cells (PSCs). Especially, defect-mediated nonradiative recombination that occurs at ...

2021

A hysteresis-free perovskite transistor with exceptional stability through molecular cross-linking and amine-based surface passivation

Mohammad Khaja Nazeeruddin, Peng Gao, Hobeom Kim

Organo-metal halide perovskite field-effect transistors present serious challenges in terms of device stability and hysteresis in the current-voltage characteristics. Migration of ions located at grain boundaries and surface defects in the perovskite film ...

ROYAL SOC CHEMISTRY2020

Perovskite Flash Memory with a Single-Layer Nanofloating Gate

Mohammad Khaja Nazeeruddin, Peng Gao, Tom Theodorus Antonius Lummen, Hobeom Kim

Here we use triple-cation metal-organic halide perovskite single crystals for the transistor channel of a flash memory device. Moreover, we design and demonstrate a 10 nm thick single-layer nanofloating gate. It consists of a ternary blend of two organic s ...

2020

Proton-transfer-induced 3D/2D hybrid perovskites suppress ion migration and reduce luminance overshoot

Mohammad Khaja Nazeeruddin, Emad Oveisi, Hobeom Kim

Perovskite light-emitting diodes (PeLEDs) based on three-dimensional (3D) polycrystalline perovskites suffer from ion migration, which causes overshoot of luminance over time during operation and reduces its operational lifetime. Here, we demonstrate 3D/2D ...

Nature Research2020

Effective Preparation of Nanoscale CH3NH3PbI3 Perovskite Photosensitizers for Mesoporous TiO2-Based Solar Cells by Successive Precursor Layer Adsorption and Reaction Process

Mohammad Khaja Nazeeruddin, Yonghui Lee, Tom Theodorus Antonius Lummen, Kyung Taek Cho, Sanghyun Paek, Iwan Zimmermann, Aron Joel Huckaba, Hobeom Kim, So-Min Yoo

Nanoscale CH3NH3PbI3 perovskite sensitizers are grown by delivering each precursor successively onto the surface of mesoporous (meso) TiO2 electrodes. Using Pb(NO3)(2) ions as a lead(II) source and CH3NH3I (MAI) for methylammonium and iodide sources, repet ...

2020

D-pi-A-Type Triazatruxene-Based Dopant-Free Hole Transporting Materials for Efficient and Stable Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Kasparas Rakstys, Sanghyun Paek, Cristina Roldán Carmona, Hiroyuki Kanda, Cansu Igci, Hobeom Kim

Three donor-pi-bridge-acceptor (D-pi-A)-type organic small molecules coded CI-B1, CI-B2, and CI-B3 are designed, synthesized, and used as dopant-free hole transporting materials (HTMs) for perovskite solar cells (PSCs). The strong electron-donating triazat ...

WILEY-V C H VERLAG GMBH2020

Gradient band structure: high performance perovskite solar cells using poly(bisphenol A anhydride-co-1,3-phenylenediamine)

Mohammad Khaja Nazeeruddin, Sanghyun Paek, Cristina Roldán Carmona, Aron Joel Huckaba, Hiroyuki Kanda, Mousa Abdulla M E Abuhelaiqa, Nadja Isabelle Desiree Klipfel, Albertus Adrian Sutanto, Hobeom Kim, Maria Cristina Momblona Rincón, Ryuji Kaneko

Surface passivation is a critical factor for improving the photovoltaic performance of perovskite solar cells. However, more robust principle investigations are required to build effective passivation strategies enabling high-performance perovskite solar c ...

Royal Society of Chemistry2020

Doped but Stable: Spirobisacridine Hole Transporting Materials for Hysteresis-Free and Stable Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Anne-Clémence Corminboeuf, Marius Franckevicius, Sanghyun Paek, Cristina Roldán Carmona, Nikita Drigo, Kun-Han Lin, Pascal Alexander Schouwink, Albertus Adrian Sutanto, Hobeom Kim, Muhammad Sohail

Four spirobisacridine (SBA) hole-transporting materials were synthesized and employed in perovskite solar cells (PSCs). The molecules bear electronically inert alkyl chains of different length and bulkiness, attached to in-plane N atoms of nearly orthogona ...

AMER CHEMICAL SOC2020

Self-Crystallized Multifunctional 2D Perovskite for Efficient and Stable Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Aron Joel Huckaba, Albertus Adrian Sutanto, Hobeom Kim

Recently, perovskite solar cells (PSC) with high power-conversion efficiency (PCE) and long-term stability have been achieved by employing 2D perovskite layers on 3D perovskite light absorbers. However, in-depth studies on the material and the interface be ...

WILEY-V C H VERLAG GMBH2020