서장원 교수

A long-standing dream in the large scale application of solar energy conversion is the fabrication of solar cells with high-efficiency and long-term stability at low cost. The realization of such practical goals depends on the architecture, process and key materials because solar cells are typically constructed from multilayer heterostructures of light harvesters, with electron and hole transporting layers as a major component. Recently, inorganic-organic hybrid lead halide perovskites have attr

In this work, we report a peculiar positive solvatochromism in the keto emission of the acceptor-substituted 2-(2'-hydroxyphenyl)benzoxazoles (HBO), which originates from the excited-state intramolecular proton transfer (ESIPT) followed by the intramolecular charge transfer (ICT) and subsequent solvent relaxation. This transient evolution of enhanced ICT characteristic triggered by ESIPT, which is first observed in this work, is responsible for the novel concept of a fast hyperpolarizability mod

In Sn-based halide perovskite solar cells (PSCs), the oxidation of Sn2+ to Sn4+ under ambient air leads to unwanted p-type doping in the perovskite film, which is a main reason for increased background carrier density and low efficiency. Here, we find that the introduction of bromide into formamidinium tin iodide (CH(NH2)2SnI3, FASnI3) lattice significantly lowers the carrier density of perovskite absorber, which is thought to be a result of reduction of Sn vacancies. It reduces the leakage curr

Abstract The energy level alignment of the perovskite and hole transporting materials (HTMs) is essential for increasing the open‐circuit voltage ( V oc ) and enhancing the performance of perovskite solar cells (PSCs). In this work, new sequentially fluorinated poly(triarylamine) polymers (PTAA, 1F‐PTAA, and 2F‐PTAA) with tuned highest occupied molecular orbital (HOMO) energy levels are developed and applied as HTMs into PSCs. The fluorination approach successfully leads to stepwise downshifting

Abstract The stability of a perovskite solar cell (PSC) is enhanced significantly by applying a customized thin‐film encapsulation (TFE). The TFE is composed of a multilayer stack of organic/inorganic layers deposited by initiated chemical vapor deposition and atomic layer deposition, respectively, whose water vapor transmission rate is on the order of 10 −4 g m −2 d −1 at an accelerated condition of 38 °C and 90% relative humidity (RH). The TFE is optimized, taking into consideration various as

CuPC-applied perovskite solar cells show excellent long-term thermal stability which is attributed to the reliable interface and intrinsic heat-resistance of CuPC.

Porous planar structure, as a new concept of low temperature processing ETL, enables to achieve unprecedented PCE in flexible unit cells and large area modules.

Recent advances in perovskite solar cells (PSCs) have resulted in greater than 23% efficiency with superior advantages such as flexibility and solution-processability, allowing PSCs to be fabricated by a high-throughput and low-cost roll-to-roll (R2R) process. The development of scalable deposition processes is crucial to realize R2R production of flexible PSCs. Gravure printing is a promising candidate with the benefit of direct printing of the desired layer with arbitrary shape and size by usi

A facile approach to make an efficient hybrid bulk heterojunction photovoltaic device with lead sulfide nanocrystals and a low-bandgap polymer is demonstarted, resulting in a power conversion efficiency of about 2–3%.

Since the first publication by Miyasaka in 2009 on the use of lead halide perovskite as a light-harvesting material (Kojima, A.; Teshima, K.; Shirai, Y.; Miyasaka, T. Organometal Halide Perovskites as Visible-Light Sensitizers for Photovoltaic Cells. J. Am. Chem. Soc. 2009, 131, 6050), unprecedented successes have been achieved and great efforts have been made in the field of perovskite solar cells (PSCs) to push the power conversion efficiency (PCE) past 25%, which corresponds to ∼80% of this m

We have designed and synthesized fluorinated indolo[3,2-<i>b</i>]indole (IDID) derivatives as crystalline hole-transporting materials (HTM) for perovskite solar cells. The fluorinated IDID backbone enables a tight molecular arrangement stacked by strong π-π interactions, leading to a higher hole mobility than that of the current HTM standard, <i>p</i>,<i>p</i>-spiro-OMeTAD, with a spherical shape and amorphous morphology. Moreover, the photoluminescence quenching in a perovskite/HTM film is more

A fast and large-area-compatible two-step deposition method for perovskite is developed to achieve over 18% for MAPbI₃.

Abstract Recent progress in highly efficient perovskite solar cells (PSCs) has been made by virtue of interfacial engineering on 3D perovskite surfaces for their defect control, however, the structural stability of the modified interface against external stimuli still remains unresolved. Herein, 4‐dimethylaminopyridine (DMAP) is introduced to develop a facile technique for selectively passivating the grain boundary (GB) and controlling the topographical boundary of the perovskite surface near th

A methodology for achieving versatile and facile ligand exchange by post-fabrication chemical treatment in PbS nanocrystal:poly(3-hexylthiophene) (P3HT) hybrid composite photovoltaic devices is demonstrated. We report a considerable improvement of the photovoltaic performance after post-fabrication chemical treatment using acetic acid to produce PbS nanocrystals surrounded by short-length ligands. Annealing induced morphological and photovoltaic performance changes in the resulting composite dev

The improved performance achieved by combining tert-butyl copper (II) phthalocyanine (CuPC) and po-spiro-OMeTAD as hole transporting material (HTM) for formamidinium lead iodide (FAPbI3)-based perovskite solar cells is reported. A device efficiency of 19.4% under standard 1 sun is obtained. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-ed