Gill Sang Han 교수

We report on reduced graphene oxide (rGO)/mesoporous (mp)-TiO2 nanocomposite based mesostructured perovskite solar cells that show an improved electron transport property owing to the reduced interfacial resistance. The amount of rGO added to the TiO2 nanoparticles electron transport layer was optimized, and their impacts on film resistivity, electron diffusion, recombination time, and photovoltaic performance were investigated. The rGO/mp-TiO2 nanocomposite film reduces interfacial resistance w

MgO ultrathin nanolayers are able to efficiently retard charge recombination in perovskite solar cells.

Hybrid organic-inorganic halide perovskites (HPs) have garnered significant attention for use in resistive switching (RS) memory devices due to their low cost, low operation voltage, high on/off ratio, and excellent mechanical properties. However, the HP-based RS memory devices continue to face several challenges owing to the short endurance and stability of the HP film. Herein, two-dimensional/three-dimensional (2D/3D) perovskite heterojunction films were prepared via a low-temperature all-solu

With skyrocketing interest and achievement of tremendous research efforts, perovskite solar cells are on the verge of commercialization. However, the stabilities of precursors and devices provide challenges for commercialization. Many researchers have dealt with these issues separately. Here, we introduce novel diphthalic anhydride-based Lewis base additives that address the precursor and device stability difficulties simultaneously. The added Lewis bases showed excellent interactions with Pb2+

An organic–inorganic perovskite solar cell (PSC) is a very promising candidate for a next-generation photovoltaic system.

Abstract A high‐quality electron transport layer (ETL) is a critical component for the realization of high‐efficiency perovskite solar cells. We developed a controllable direct‐contact reaction process to prepare a chlorinated SnO 2 (SnO 2 ‐Cl) ETL. It is unique in that (a) 1′2‐dichlorobenzene is used to provide more reactive Cl radicals for more in‐depth passivation; (b) it does not introduce any impurities other than chlorine. It is found that the chlorine modification significantly improves t

Abstract Formamidinium lead triiodide‐based perovskite solar cells have emerged as one of the most promising candidates that can be potentially used to develop photovoltaic technologies in the future. The commercial use of perovskite solar cell modules (PSCMs) is limited as it is challenging to fabricate high‐quality, efficient, and stable large‐area perovskite light‐absorbing films. Heptadecafluorooctanesulfonic acid tetraethylammonium salt (HFSTT), containing fluorinated long alkyl chains as h

Perovskite solar cells (PSCs) have shown remarkable advancements and achieved impressive power conversion efficiencies since their initial introduction in 2012. However, challenges regarding stability, quality, and sustainability must be addressed for their successful commercial use. This review analyses the recent studies and challenges related to the operating life and end-of-life utilization of PSCs. Strategies to enhance the stability and mitigate the toxic Pb leakage in operational and recy

We report highly bendable and efficient perovskite solar cells (PSCs) that use thermally oxidized layer of Ti metal plate as an electron transport layer (ETL). The power conversion efficiency (PCE) of flexible PSCs reaches 14.9% with a short-circuit current density (J_sc) of 17.9 mA/cm², open-circuit voltage (V_oc) of 1.09, and fill factor (ff) of 0.74. Moreover, the Ti metal-based PSCs exhibit a superior fatigue resistance over indium tin oxide/poly(ethylene terep

We demonstrate high-performance perovskite solar cells with excellent electron transport properties using a one-dimensional (1D) electron transport layer (ETL). The 1D array-based ETL is comprised of 1D SnO2 nanowires (NWs) array grown on a F:SnO2 transparent conducting oxide substrate and rutile TiO2 nanoshells epitaxially grown on the surface of the 1D SnO2 NWs. The optimized devices show more than 95% internal quantum yield at 750 nm, and a power conversion efficiency (PCE) of 14.2%. The high

Abstract Mixed‐halide perovskites have emerged as outstanding light absorbers that enable the fabrication of efficient solar cells; however, their instability hinders the commercialization of such systems. Grain‐boundary (GB) defects and lattice tensile strain are critical intrinsic‐instability factors in polycrystalline perovskite films. In this study, the light‐induced cross‐linking of acrylamide (Am) monomers with non‐crystalline perovskite films is used to fabricate highly efficient and stab

Hydroxyapatite (HAp) particles with various morphologies such as sphere, rod, whisker, and platelet have attracted a great deal of scientific and technological interest for their broad utilization as reinforcing agents in bone cement, bone fillers, drug carriers, and adsorbents for chromatography. In this Article, a simple method to control the morphology of HAp particles by adjusting the initial pH of precursors and the amount of gelatin and urea additions is introduced. Initially formed calciu

An electron-transport layer (ETL) that selectively collects photogenerated electrons is an important constituent of halide perovskite solar cells (PSCs). Although TiO₂ films are widely used as ETL of PSCs, the processing of TiO₂ films with high electron mobility requires high-temperature annealing and TiO₂ dissociates the perovskite layer through a photocatalytic reaction. Here, we report an effective surface-modification method of a room-temperature processed Zn