Showing papers by "Jun Hong Noh published in 2014"
TL;DR: A bilayer architecture comprising the key features of mesoscopic and planar structures obtained by a fully solution-based process is reported, providing important progress towards the understanding of the role of solution-processing in the realization of low-cost and highly efficient perovskite solar cells.
Abstract: The performance of solar cells based on organic–inorganic perovskites strongly depends on the device architecture and processing conditions. It is now shown that solvent engineering enables the deposition of very dense perovskite layers on mesoporous titania, leading to photovoltaic devices with a high light-conversion efficiency and no hysteresis.
5,684 citations
TL;DR: Three spiro-OMeTAD derivatives have been synthesized and characterized by (1)H/(13)C NMR spectroscopy and mass spectrometry, and their performances were compared for the fabrication of mesoporous TiO2/CH3NH3PbI3/HTM/Au solar cells, where the cell performance was dependent on the positions of the OMe substituents.
Abstract: Three spiro-OMeTAD derivatives have been synthesized and characterized by (1)H/(13)C NMR spectroscopy and mass spectrometry The optical and electronic properties of the derivatives were modified by changing the positions of the two methoxy substituents in each of the quadrants, as monitored by UV-vis spectroscopy and cyclic voltammetry measurements The derivatives were employed as hole-transporting materials (HTMs), and their performances were compared for the fabrication of mesoporous TiO2/CH3NH3PbI3/HTM/Au solar cells Surprisingly, the cell performance was dependent on the positions of the OMe substituents The derivative with o-OMe substituents showed highly improved performance by exhibiting a short-circuit current density of 212 mA/cm(2), an open-circuit voltage of 102 V, and a fill factor of 776% under 1 sun illumination (100 mW/cm(2)), which resulted in an overall power conversion efficiency (PCE) of 167%, compared to ~15% for conventional p-OMe substituents The PCE of 167% is the highest value reported to date for perovskite-based solar cells with spiro-OMeTAD
690 citations
TL;DR: In this paper, the effects of the energy level between CH3NH3(= MA)PbI3 and MAPbBr3 and a series of triarylamine polymer derivatives containing fluorene and indenofluorene, which have different highest occupied molecular orbital (HOMO) levels, in terms of the photovoltaic behavior were investigated.
Abstract: Besides the generated photocurrent as a key factor that impacts the efficiency of solar cells, the produced photovoltage and fill factor are also of critical importance. Therefore, understanding and optimization of the open-circuit voltage (Voc) of perovskite solar cells, especially with an architecture consisting of mesoporous (mp)-TiO2/perovskite/hole transporting materials (HTMs), are required to further improve the conversion efficiency. In this work, we study the effects of the energy level between CH3NH3(= MA)PbI3 and MAPbBr3 and a series of triarylamine polymer derivatives containing fluorene and indenofluorene, which have different highest occupied molecular orbital (HOMO) levels, in terms of the photovoltaic behaviour. The voltage output of the device is found to be dependent on the higher energy level of perovskite solar absorbers as well as the HOMO level of the HTMs. The combination of MAPbBr3 and a deep-HOMO HTM leads to a high photovoltage of 1.40 V, with a fill factor of 79% and an energy conversion efficiency of up to 6.7%, which is the highest value reported to date for MAPbBr3 perovskite solar cells.
668 citations
TL;DR: In this paper, a planar perovskite-PCBM solar cell with CH3NH3PbI3 film and a thin PCBM film is fabricated by the solution-process at low temperature.
Abstract: Highly efficient p–i–n perovskite solar cells employing a flat and thick CH3NH3PbI3 film and a thin PCBM film are fabricated by the solution-process at low temperature. Through attainment of optimized PCBM thickness and insertion of the LiF interlayer, the unit cell shows 14.1% of overall power conversion efficiency (PCE) with a Jsc of 20.7 mA cm−2, a Voc of 0.866 V, and a FF of 78.3% under AM 1.5G 100 mW cm−2 conditions, while a larger area 10 cell serially connected module (10 × 10 cm2) shows an 8.7% PCE. These PCE values are the highest reported to date for the planar perovskite–PCBM solar cells.
605 citations
TL;DR: In this article, the light harvesting Sb2S3 surface on mesoporous-TiO2 in inorganic-organic heterojunction solar cells is sulfurized with thioacetamide (TA).
Abstract: The light-harvesting Sb2S3 surface on mesoporous-TiO2 in inorganic–organic heterojunction solar cells is sulfurized with thioacetamide (TA). The photovoltaic performances are compared before and after TA treatment, and the state of the Sb2S3 is investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and deep-level transient spectroscopy (DLTS). Although there are no differences in crystallinity and composition, the TA-treated solar cells exhibit significantly enhanced performance compared to pristine Sb2S3-sensitized solar cells. From DLTS analysis, the performance enhancement is mainly attributed to the extinction of trap sites, which are present at a density of (2–5) × 1014 cm−3 in Sb2S3, by TA treatment. Through such a simple treatment, the cell records an overall power conversion efficiency (PCE) of 7.5% through a metal mask under simulated illumination (AM 1.5G, 100 mW cm–2) with a very high open circuit voltage of 711.0 mV. This PCE is, thus far, the highest reported for fully solid-state chalcogenide-sensitized solar cells.
417 citations
TL;DR: The results of this study imply that the developed approach has a high potential as a simple and effective route for the fabrication of efficient and inexpensive solar cells.
Abstract: The photovoltaic performance of Sb2Se3-sensitized heterojunction solar cells, which were fabricated by a simple deposition of Sb2Se3 on mesoporous TiO2 by an approach that features multiple cycles of spin coating with a single-source precursor solution and thermal decomposition, is reported. Poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt-4,7(2,1,3-benzothioadiazole)] was used as the hole-transporting material. The most efficient cell exhibited a short-circuit current density of 22.3 mA cm−2, an open-circuit voltage of 304.5 mV, and a fill factor of 47.2 %, yielding a power conversion efficiency of 3.21 % under standard test conditions (irradiation of 1000 W m−2, air mass=1.5 G). The results of this study imply that the developed approach has a high potential as a simple and effective route for the fabrication of efficient and inexpensive solar cells.
150 citations
TL;DR: Seok et al. as mentioned in this paper proposed an energy-efficient approach to solve the problem of energy efficiency in the context of chemical engineering, where the energy efficiency is measured by the amount of energy consumed.
Abstract: Dr. Y. C. Choi, Dr. Y. H. Lee, Dr. J. H. Noh, Dr. T. N. Mandal, W. S. Yang, Dr. S. I. Seok Division of Advanced Materials Korea Research Institute of Chemical Technology 141 Gajeong-Ro, Yuseong-Gu, Daejeon , 305.600 , Republic of Korea Prof. S. H. Im Department of Chemical Engineering Kyung Hee University oungin-si , Y 446–701 , Republic of Korea Prof. S. I. Seok Department of Energy Science Sungkyunkwan University Suwon , 440–746 , Republic of Korea E-mail: seoksi@skku.edu
114 citations
TL;DR: In this article, a column-like porous nanostructure consisting of nanoparticles 30-50nm in size with open channels of pores between the columns is presented for photoelectrochemical water oxidation that is easily synthesized by pulsed laser deposition (PLD) method.
53 citations
TL;DR: In this article, a template-induced self-organizing sol-gel process was shown to be a useful technique for depositing mesoporous photoanodes in the fabrication of perovskite-based solar cells.
Abstract: A well-aligned mesoporous thin layer was formed by spin-coating followed by the burn-out of its organic components at 500 °C. This film, prepared by an inorganic sol–gel process using block copolymers as a sacrificial template, showed mesoporous (mp) and crack-free layers with various pore sizes depending on the amount of 1,3,5-trimethylbenzene (TMB), which acted as a swelling agent. The mesoporous photoanodes were used in the fabrication of CH3NH3Pb(I0.9Br0.1)3 perovskite-based solar cells. The cells showed overall power conversion efficiencies of 11.7% and 12.8% with the 10 and 15 nm mp-layers, respectively. The superior performance shown in the 15 nm mp-layers may be attributed to the easier filling of CH3NH3Pb(I0.9Br0.1)3 by bigger pore sizes, and the efficiency is comparable with that of the reference cell fabricated by TiO2 paste. This template-induced self-organizing sol–gel process was shown to be a useful technique for depositing mesoporous photoanodes in the fabrication of perovskite-based solar...
46 citations
Patent•
21 Mar 2014
TL;DR: In this paper, a solar cell consisting of a first electrode, a complex layer, a light absorber, a hole conductive layer, and a second electrode is described, where the first electrode is the light absorbing layer and the second is the hole absorbing layer.
Abstract: The present invention relates to a solar cell and, more specifically, to a solar cell comprising: a first electrode; a complex layer located at the first electrode and containing a light absorber; an optical absorption structure located at the complex layer and consisting of the light absorber; a hole conductive layer located at the upper part of the optical absorption structure; and a second electrode located at the upper part of the hole conductive layer. [Reference numerals] (AA) Light absorber thin film; (BB) Composite layer
28 citations
TL;DR: TiO2 nanoparticle (NP)/ITO nanowire (NW) nanocomposites for use as photoelectrode materials were fabricated to improve the charge collection efficiency in solid state dye sensitized solar cells (ss-DSSCs) to boost current densities.
Abstract: TiO2 nanoparticle (NP)/ITO nanowire (NW) nanocomposites for use as photoelectrode materials were fabricated to improve the charge collection efficiency in solid state dye sensitized solar cells (ss-DSSCs). The average current density for ss-DSSCs containing TiO2 NP/ITO NW arrays was 7.2 mA cm−2 that was 98% higher than that for the conventional TiO2 NP ss-DSSCs. The intensity modulated photocurrent spectroscopy (IMPS) and intensity modulated photovoltage spectroscopy (IMVS) studies exhibited that the electron diffusion length of TiO2 NP/ITO-NW nanocomposite ss-DSSCs was in the range of 4.3–5.6 μm, longer than that of TiO2 NP solar cells (2.6–4.1 μm). The longer diffusion length was responsible for the boosted current densities of TiO2 NP/ITO NW nanocomposite ss-DSSCs. We also employed the TiO2 NP/ITO NW nanocomposite photoelectrode to inorganic–organic perovskite solar cells whose energy conversion efficiency was 7.5%.
Patent•
23 Dec 2014
TL;DR: In this paper, the precursor of an inorganic/organic hybrid perovskite compound is defined as a mixture of an organic positive ion and a metal positive ion, a halogen negative ion, and a guest molecule.
Abstract: Provided is a precursor of an inorganic/organic hybrid perovskite compound, and the precursor of the precursor of the inorganic/organic hybrid perovskite compound according to an exemplary embodiment of the present invention includes an organic positive ion, a metal positive ion, a halogen negative ion, and a guest molecule (GM).
Patent•
10 Jan 2014
TL;DR: In this article, a solar cell including a first electrode, an electron transport layer positioned on the first electrode; a light absorber, a hole transport layer; and a second electrode, wherein the light absorbers contains a solid-solution of at least two organic-metal halides with a perovskite structure, having different compositions from each other.
Abstract: Provided is a solar cell including: a first electrode; an electron transport layer positioned on the first electrode; a light absorber; a hole transport layer; and a second electrode, wherein the light absorber contains a solid-solution of at least two organic-metal halides with a perovskite structure, having different compositions from each other.
TL;DR: In this paper, the hierarchical In 2 O 3 :Sn/TiO 2 /CdS heterojunction nanowire array photoanode was proposed to provide a short travel distance for charge carrier and long light absorption pathway.
TL;DR: This work has demonstrated an allsolid-state sensitized solar cell with a relatively thin photoelectrode and found that the generated charge carriers in the PbS CQDs could be transported in a radial direction, which is the shortest pathway to deliver the charge carriers into the electrode.
Abstract: Colloidal quantum dots (CQDs) have been intensively studied owing to their unique optical and physical properties such as convenient electronic bandgap control by the quantum confinement effect, strong absorption over broad wavelength regions, an intrinsically large dipole moment, and multiple exciton generation by impact ionization. In particular, it is expected that the unique properties of CQDs will greatly improve solar cells because their solution processability at relatively lower processing temperatures can reduce the fabrication cost and yield flexible thin-film solar cells. Accordingly, intensive studies have been performed to develop efficient CQD solar cells with inorganic metal chalcogenides such as CdS(e), PbS(e), HgTe, and CuInTe(Se). Among them, near-infrared (NIR)-responsive PbS CQDs have been of great interest because PbS has a low bulk energy bandgap of ~0.4 eV and a large Bohr radius of 18 nm. Since Gr tzel et al. first reported dye-sensitized solar cells, these sensitized solar cells have been intensively studied over the past two decades in an effort to develop cost-effective solar cells. Sensitized solar cells are composed of an electron conductor, a sensitizer, and a hole conductor. This setup allows the generated electron–hole pairs to quickly separate into electron conductors and hole conductors. The probability of recombination is thus greatly reduced, even when relatively impure materials are used. However, the conventional Ru dyes and liquid electrolytes used in dye-sensitized solar cells might limit the ability to fabricate flexible optoelectronics because the weak absorption coefficient of Ru dyes requires a mesoporous TiO2 electrode over 10 mm thick to fully absorb the light. Further, the liquid electrolyte could potentially leak when subjected to bending. Therefore, it is desirable to develop an allsolid-state sensitized solar cell with a relatively thin photoelectrode. As part of an effort to develop all-solid-state inorganic CQDsensitized solar cells (SSCs), we previously demonstrated PbS CQD-SSCs with a device architecture of mesoporous TiO2/PbS CQDs and poly-3-hexylthiophene (P3HT) and spiro-MeOTAD [2,2’,7,7’-tetrakis(N,N-di-p-methoxyphenylamine)-9,9’-spirobifluorene] , which serve as organic hole-transporting materials (HTMs). From our previous studies, we found that the PbS CQDs can be more densely packed in the top section of a mesoporous TiO2 electrode, even though some PbS CQDs successfully infiltrate into the bottom section of the TiO2 electrode and the effectiveness of the organic HTMs is reduced by the infiltration of the HTMs into the narrow pores of the PbS CQDs deposited on the mesoporous TiO2. Therefore, we considered that a one-dimensional (1D) TiO2 electrode would provide sufficient pore space, enabling a good penetration of HTM into the surface of the PbS CQD/TiO2 electrode. Using a device architecture of 1D TiO2 nanorod electrode/PbS CQD/P3HT HTM, the generated charge carriers in the PbS CQDs could be transported in a radial direction, which is the shortest pathway to deliver the charge carriers into the electrode. Therefore, we could significantly improve the fill factor as compared to conventional mesoscopic TiO2 nanoparticle-based PbS CQD-SSCs. Scheme 1 shows an illustration of the PbS CQD-SSCs with radial-directional charge transport. We thought that the shortest pathway to extract the charge carriers generated in multistacked PbS CQDs was to use 1D TiO2 and separate the charge carriers in the radial direction. Holes can be efficiently transported to the Au counter electrode through the P3HT HTM and PEDOT:PSS hole-conducting layer and at the same time the electrons can be done as well. Upon illumination with solar light, the PbS CQDs generate electron–hole pairs and the generated electrons (holes) are injected into the TiO2 photoelectrode (P3HT HTM). When an n–p heterojunction is made by n-type TiO2 and p-type PbS CQDs stacked into multiple layers, the charge carriers have many opportunities to recom[a] S. Kim, J. H. Heo, Dr. J. H. Noh, Prof. S. I. Seok Solar Energy Materials Research Group Division of Advanced Materials Korea Research Institute of Chemical Technology 141 Gajeong-ro, Yuseong-gu Daejeon 305-600 (Korea) E-mail : seoksi@krict.re.kr [b] S. Kim, Prof. S.-W. Kim Department of Molecular Science and Technology Ajou University Suwon, 443-749 (Korea) E-mail : swkim@ajou.ac.kr [c] J. H. Heo, Prof. S. H. Im Department of Chemical Engineering College of Engineering Kyung Hee University 1 Seochon-dong, Giheung-gu Yongin-si, Gyeonggi-do 446-701 (Republic of Korea) E-mail : imromy@khu.ac.kr [d] Prof. S. I. Seok Department of Energy Science Sungkyunkwan University Suwon 440-746 (Korea) E-mail : seoksi@skku.edu [] Equal contributions. Supporting Information for this article is available on the WWW under http://dx.doi.org/10.1002/cphc.201300825.
TL;DR: In this paper, hierarchical organized nanostructures were fabricated by growing SnO2 nanoparticles on a fluorine-doped tin oxide/glass substrate via a laser ablation method.
Abstract: Hierarchically organized nanostructures were fabricated by growing SnO2 nanoparticles on a fluorine-doped tin oxide/glass substrate via a laser ablation method. Cauliflower-like clusters consisting of agglomerated nanoparticles were deposited and aligned with respect to the substrate with a large internal surface area and open channels of pores. The morphological changes of SnO2 nanostructured films were investigated as a function of the oxygen working pressure in the range of 100–500 mTorr. A nanostructured scaffold prepared at an oxygen working pressure of 100 mTorr exhibited the best photoelectrochemical (PEC) performance. A Ti:Fe2O3-SnO2 nanostructured photoanode showed the photocurrent that was 34% larger than that of a Ti:Fe2O3 flat photoanode when the amount of Ti:Fe2O3 sensitizer was identical for the two photoanodes. The larger surface area and longer electron lifetime of the Ti:Fe2O3-SnO2 nanostructured photoanode explains its improved PEC performance.
Patent•
21 Jul 2014
TL;DR: In this paper, a solar cell consisting of a first electrode, an electron transport layer, a light absorption body, a hole transport layer and a second electrode is described, which contains an organic metal halide solid solution of two or more perovskite structures.
Abstract: The present invention relates to a solar cell which includes a first electrode, an electron transport layer which is located on the first electrode, a light absorption body, a hole transport layer, and a second electrode. The light absorption body contains an organic metal halide solid solution of two or more perovskite structures which have different compositions from each other.
Patent•
21 Jul 2014
TL;DR: In this article, a method for manufacturing a solar cell according to the present invention comprises the steps of forming an electron transport layer above a first electrode, forming a hole conduction layer by coating and drying a hole transport solution in which an organic hole transport material is dissolved.
Abstract: A method for manufacturing a solar cell according to the present invention comprises the steps of a) forming an electron transport layer above a first electrode; b) forming a light absorption body by coating a light absorption body solution for forming the light absorption body comprising an organic-metal halide having a perovskite structure, wherein an organic halide and a metal halide are dissolved in the solution so as to have a non-stoichiometric ratio with respect to the organic-metal halide; c) forming a hole conduction layer by coating and drying a hole transport solution in which an organic hole transport material is dissolved; and d) forming a second electrode, which is a counter electrode of the first electrode, above the hole conduction layer.
Patent•
10 Jan 2014
TL;DR: In this article, a method for manufacturing a solar cell including an electron transport layer on a first electrode, forming a hole conduction layer by applying and drying a hole transport solution in which an organic hole transport material is dissolved, and forming a second electrode which is a counter electrode of the first electrode on the hole-conduction layer.
Abstract: Provided is a method for manufacturing a solar cell including: a) forming an electron transport layer on a first electrode; b) forming a light absorber by applying a light absorber solution as a solution for forming a light absorber containing an organic-metal halide having a perovskite structure, the light absorber solution containing an organic halide and a metal halide dissolved therein so as to have a non-stoichiometric ratio based on the organic-metal halide; c) forming a hole conduction layer by applying and drying a hole transport solution in which an organic hole transport material is dissolved; and d) forming a second electrode, which is a counter electrode of the first electrode, on the hole conduction layer.
TL;DR: One dimensional (1-D) transparent-conducting-oxide arrays coated with light- absorption semiconductors to simultaneously maximize light harvesting and charge collection in a photoelectrochemical (PEC) system are reported.
Abstract: We report one dimensional (1-D) transparent-conducting-oxide arrays coated with light-absorbing semiconductors to simultaneously maximize light harvesting and charge collection in a photoelectrochemical (PEC) system. Tin-doped indium oxide (ITO) nanowire (NW) arrays are prepared on ITO thin-film substrates as the transparent-conducting-oxide, and TiO2 or CdSe/CdS/TiO2 thin layers were coated on the ITO NW arrays as the solar light-absorbing layers. The optimal PEC performance, 0.85% under 100 mW cm−2 of light illumination, is obtained from ∼30 μm-long ITO NW, which is covered with ∼20 nm-thick TiO2 nanoshell. We finally demonstrate that the ITO NW-based photoelectrode is also compatible with one of the most efficient visible-light sensitizers, the CdS/CdSe quantum dot. Our approach using the transparent conducting 1-D array has wide potential to improve the PEC performances of conventional semiconducting materials through liberation from the poor charge transport.
Patent•
01 Jul 2014
TL;DR: In this paper, a solar cell including a first electrode, a composite layer including a light absorber impregnated thereinto, a light absorption structure positioned on the composite layer and composed of a light absorbing, a hole conductive layer, and a second electrode position on the hole conductively layer.
Abstract: Provided is a solar cell including: a first electrode; a composite layer positioned on the first electrode and including a light absorber impregnated thereinto; a light absorption structure positioned on the composite layer and composed of a light absorber; a hole conductive layer positioned on the light absorption structure; and a second electrode positioned on the hole conductive layer.
Patent•
16 Oct 2014
TL;DR: In this paper, a method and device for producing a titanium oxide nanostructure which are straightforward and at the same time allow sustained synthesis is presented, where the titanium oxide is made by introducing a titanium-containing precursor solution into a reaction chamber and by then applying a pulse-type power source so as to cause a plasma arc discharge.
Abstract: Provided are a method and device for producing a titanium oxide nanostructure which are straightforward and at the same time allow sustained synthesis. In the production method for a titanium oxide nanostructure according to the present invention, the titanium oxide nanostructure is made by introducing a titanium-containing precursor solution into a reaction chamber and by then applying a pulse-type power source so as to cause a plasma arc discharge. According to the present invention, there is no need to constitute an electrode from a composition constituting a nanostructure and there is no need for any additional gas supply, and thus, as compared with existing methods, the present invention is straightforward, simple and saves on processing costs and, in addition, allows volume production.