Hyung Do Kim 교수

Perovskite solar cells exhibit improved photovoltaic parameters with increasing perovskite grain size. The larger photocurrent is due to the enhanced absorption efficiency for thicker perovskite layers. The larger open-circuit voltage (VOC ) is ascribed to the reduced trap-assisted recombination for the larger grains. As a result, the power conversion efficiency exceeds 19% at best. Further improvement in VOC would be possible if the trap density were reduced.

Organic–inorganic perovskite solar cells based on tin halides exhibit a small open-circuit voltage (VOC) because of a large photon energy loss from band-gap energy, as large as 0.8–1.0 eV. In this study, we discussed the origin of the VOC loss in CH3NH3SnI3-based devices by measuring the temperature dependence of VOC. As a result, we found that the large loss in VOC is mainly due to the surface recombination at the interface rather than the bulk recombination in the perovskites. Organic–inorgani

Abstract Perovskite solar cells (PSCs) are considered to be one of the most promising solar energy harvesters owing to their high power conversion efficiency (PCE). To increase their PCE even further, additives are used; however, some of these additives pose certain disadvantages, which limit their applications to PSCs. Therefore, in this study, the nature‐inspired ecofriendly M13 bacteriophage is genetically engineered to maximize its performance as a perovskite crystal growth template and as a

Abstract This review addresses the self‐healing effects in perovskite solar cells (PSCs), emphasizing the significance of chemical and physical bonding as core mechanisms. Polymeric additives play a vital role in inducing self‐healing phenomena along with the intrinsic properties of perovskite materials, both of which are discussed herein. As a relatively underexplored area, the self‐healing effect induced by polymeric additives in PSCs is reviewed from a chemical perspective. The chemical bonds

In this study, the origin of the fill factor (FF) in lead-halide perovskite solar cells is discussed based on different thicknesses of 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9-spirobifluorene (spiro-OMeTAD) as the hole-transporting layer (HTL). As the thickness of HTL is decreased, FF increases and hence, the photovoltaic performance is also improved. This is mainly ascribed to the reduced series resistance with decreasing HTL thickness. Such improvement in FF is examined on the basis

Herein, the open-circuit voltage (V_OC) loss in both polymer solar cells and perovskite solar cells is quantitatively analyzed by measuring the temperature dependence of V_OC to discuss the difference in the primary loss mechanism of V_OC between them. As a result, the photon energy loss for polymer solar cells is in the range of about 0.7-1.4 eV, which is ascribed to temperature-independent and -dependent loss mechanisms, while that for perovskite solar cells is as

Ternary hybrid solar cells based on zinc oxide with wide bandgap poly(3-hexylthiophene) (P3HT) and narrow bandgap poly[2,3-bis(3-octyloxyphenyl)quinoxaline-5,8-diyl-alt-thiophene-2,5-diyl] (PTQ1) exhibit improved photovoltaic performance compared to that of individual binary hybrid solar cells. The increase in the photocurrent is partly due to the complementary absorption bands, which can extend the light-harvesting range from visible to near-infrared regions, and partly due to efficient energy

Endohedral metallofullerenes (EMFs) showcase unique properties such as their capacity to stabilize isolated metal atoms and reactive metal clusters, rendering them highly appealing for diverse applications, most notably in electronic devices. This perspective examines EMFs in next-generation thin-film devices, highlighting significant discoveries in device applications that incorporate EMFs. It casts a spotlight on significant advancements in device applications that integrate EMFs, with an acut

Light-harvesting efficiency can be prominently increased by using ternary blend polymer solar cells, in which a wide-bandgap crystalline polymer is incorporated into a binary blend of a low-bandgap polymer and a fullerene derivative. This is partly due to the complementary absorption bands over a wide wavelength range, and partly ascribed to the thick photoactive layer. As a result, the best power conversion efficiency of 9.40% was obtained for the ternary blend device with a thickness of ≈300 n

Aqueous metal batteries have emerged as a promising alternative to lithium-ion batteries, offering enhanced safety through the use of aqueous electrolytes. Manganese-ion battery systems remain underexplored despite the low manganese redox potential of -1.19 V (vs the standard hydrogen electrode) as well as high operating voltage and capacity. In this study, a rhombohedral zinc Prussian blue analog (ZnHCF) is investigated for the first time as a cathode material for manganese-ion batteries, demon

One of the most challenging issues facing the organic photovoltaic community is to realize a high fill factor (FF) even with thick active layers. This is because the thick active layer is beneficial for photon absorption but makes charge collection difficult, which is primarily restricted by nongeminate recombination in solar cells. In this work, we have studied nongeminate recombination in four kinds of polymer solar cells based on blends of donor-conjugated polymers with different crystallinit

Abstract Understanding photon energy loss caused by the charge recombination in ternary blend polymer solar cells based on nonfullerene acceptors (NFAs) is crucial for achieving further improvements in their device performance. In such a ternary system, however, the two types of donor/acceptor interface coexist, making it more difficult to analyze the photon energy loss. Here, we have focused on the origin of the voltage loss behind a high open‐circuit voltage ( V OC ) in ternary blend devices b