Publications de Jeong-Hyeok Im

Silver Bismuth Iodides for Photovoltaic Applications: Insights from Ab Initio Calculations and Experimental Analysis

Michael Graetzel, Ursula Röthlisberger, Jovana Milic, Marko Mladenovic, Mohammad Ibrahim Dar, Jingshan Luo, Jeong-Hyeok Im, Farzaneh Jahanbakhshi

American Chemical Society (ACS)2025

Bifunctional Organic Spacers for Formamidinium-Based Hybrid Dion-Jacobson Two-Dimensional Perovskite Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Jovana Milic, Ulf Anders Hagfeldt, Mohammad Ibrahim Dar, Peng Wang, Yuhang Liu, Jiyoun Seo, Amita Ummadisingu, Yang Li

Three-dimensional (3D) perovskite materials display remarkable potential in photovoltaics owing to their superior solar-to-electric power conversion efficiency, with current efforts focused on improving stability. Two-dimensional (2D) perovskite analogues ...

AMER CHEMICAL SOC2019

Supramolecular Engineering for Formamidinium-Based Layered 2D Perovskite Solar Cells: Structural Complexity and Dynamics Revealed by Solid-State NMR Spectroscopy

Michael Graetzel, Shaik Mohammed Zakeeruddin, David Lyndon Emsley, Jovana Milic, Mohammad Ibrahim Dar, Dominik Józef Kubicki, Jiyoun Seo, Yang Li, Amita Ummadisingu, Jeong-Hyeok Im

Perovskite solar cells are one of the most promising photovoltaic technologies, although their molecular level design and stability toward environmental factors remain a challenge. Layered 2D Ruddlesden-Popper perovskite phases feature an organic spacer bi ...

WILEY-V C H VERLAG GMBH2019

Photodetector

Mohammad Khaja Nazeeruddin, Thomas Moehl, Konrad Domanski, Jeong-Hyeok Im

The present invention concerns a device for room temperature reverse-bias operation photo-detection. The device comprising: - a planar first electrode extending in a planar direction; - a second electrode positioned above the first electrode in a direction ...

2016

Analysing the effect of crystal size and structure in highly efficient CH3NH3PbI3 perovskite solar cells by spatially resolved photo- and electroluminescence imaging

Michael Graetzel, Jeong-Hyeok Im

CH3NH3PbI3 perovskite solar cells with a mesoporous TiO2 layer and spiro-MeOTAD as a hole transport layer (HTL) with three different CH3NH3I concentrations (0.032 M, 0.044 M and 0.063 M) were investigated. Strong variations in crystal size and morphology r ...

Royal Society of Chemistry2015

Nanowire Perovskite Solar Cell

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Peng Gao, Jingshan Luo, Thomas Moehl, Norman Pellet, Marius Franckevicius, Jeong-Hyeok Im

Organolead iodide perovskite, CH3NH3PbI3, was prepared in the form of nanowire by means of a small quantity of aprotic solvent in two-step spin-coating procedure. One-dimensional nanowire perovskite with the mean diameter of 100 nm showed faster carrier se ...

American Chemical Society2015

Growth of CH3NH3PbI3 cuboids with controlled size for high-efficiency perovskite solar cells

Michael Graetzel, Norman Pellet, Jeong-Hyeok Im

Perovskite solar cells with submicrometre-thick CH3NH3PbI3 or CH3NH3PbI3-xClx active layers show a power conversion efficiency as high as 15%. However, compared to the best-performing device, the average efficiency was as low as 12%, with a large standard ...

Nature Publishing Group2014

Water photolysis at 12.3% efficiency via perovskite photovoltaics and Earth-abundant catalysts

Michael Graetzel, Mohammad Khaja Nazeeruddin, Jingshan Luo, Matthew Thomas Mayer, Stanley David Tilley, Marcel Roland Schreier, Jeong-Hyeok Im

Although sunlight-driven water splitting is a promising route to sustainable hydrogen fuel production, widespread implementation is hampered by the expense of the necessary photovoltaic and photoelectrochemical apparatus. Here, we describe a highly efficie ...

American Association for the Advancement of Science2014

Strong Photocurrent Amplification in Perovskite Solar Cells with a Porous TiO2 Blocking Layer under Reverse Bias

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Thomas Moehl, Yonghui Lee, Fabrizio Giordano, Konrad Domanski, Leo-Philipp Heiniger, Jeong-Hyeok Im

We investigate two different types of TiO2 blocking layer (BL) deposition techniques commonly used in solid-state methylammonium lead triiodide perovskite (MaPbI(3))-based solar cells. Although these BLs lead to similar photovoltaic device performance, the ...

Amer Chemical Soc2014

Lead Iodide Perovskite Sensitized All-Solid-State Submicron Thin Film Mesoscopic Solar Cell with Efficiency Exceeding 9%

Michael Graetzel, Jacques-Edouard Moser, Jun Ho Yum, Arianna Marchioro, Robin Humphry-Baker, Thomas Moehl, Soo-Jin Moon, Jeong-Hyeok Im

We report on solid-state mesoscopic heterojunction solar cells employing nanoparticles (NPs) of methyl ammonium lead iodide (CH3NH3)PbI3 as light harvesters. The perovskite NPs were produced by reaction of methylammonium iodide with PbI2 and deposited onto ...

2012