정재웅 교수

Low-temperature, solution-processable Cu-doped NiOX (Cu:NiOx ), prepared via combustion chemistry, is demonstrated as an excellent hole-transporting layer (HTL) for thin-film perovskite solar cells (PVSCs). Its good crystallinity, conductivity, and hole-extraction properties enable the derived PVSC to have a high power conversion efficiency (PCE) of 17.74%. Its general applicability for various elecrode materials is also revealed.

Fluorinated n-type conjugated polymers are used as efficient electron acceptor to demonstrate high-performance all-polymer solar cells. The exciton generation, dissociation, and charge-transporting properties of blend films are improved by using these fluorinated n-type polymers to result in enhanced photocurrent and suppressed charge recombination.

High-performance planar heterojunction perovskite (CH3NH3PbI3) solar cell (PVSC) is demonstrated by utilizing CuSCN as a hole-transporting layer. Efficient hole-transport and hole-extraction at the CuSCN/CH3NH3PbI3 interface facilitate the PVSCs to reach 16% power conversion efficiency (PCE). In addition, excellent transparency of CuSCN enables high-performance semitransparent PVSC (10% PCE and 25% average visible transmittance) to be realized. As a service to our authors and readers, this journ

High performance planar-heterojunction (PHJ) perovskite (CH3NH3PbI3) solar cells fabricated through low-temperature annealing are demonstrated. Simple spin-coating with an optimized solvent washing process readily forms homogeneous and crystalline perovskite thin films. The perovskite films fabricated via this solvent washing process show a low dependence on annealing temperature in achieving high crystallinity and large grain size, prerequisites for high efficiency perovskite solar cells. The s

A new low bandgap conjugated polymer (PDTTDPP) comprising dithieno[3,2-b:2′,3′-d]thiophene (DTT) and diketopyrrolo[3,4-c]pyrrole (DPP) showed an outstanding hole mobility of 0.60 cm2 V−1 s−1 in organic field effect transistors without post-treatment, and a promising power conversion efficiency of 6.05% with PC71BM in organic photovoltaics.

An effective approach to extend the light absorption range of conjugated polymers for high performance photovoltaics is synthesis of copolymers composed of at least two different chromophores with a complementary absorption range. For this purpose, we synthesized random conjugated copolymers consisting of DPP and isoindigo as co-electron accepting units in donor–acceptor type conjugated copolymers. The random copolymers exhibited both broad light absorption and low-lying HOMO level, which contri

The formation of a self-assembled buffer layer (fullerene-end-capped poly(ethylene glycol); PEG-C60) in a bulk heterojunction active layer enhances the performance and oxidative stability of polymer solar cells with high-work-function metal cathodes.

Small molecules composed of benzothiadiazole and diketopyrrolopyrrole have affirmative optoelectronic properties as non-fullerene electron acceptors in photovoltaic device such as high crystallinity, decent electron mobility, a low bandgap, and proper molecular energy levels. The organic solar cell device combined with PTB7 as an electron donor exhibits a promising power conversion efficiency of 5.0%, demonstrating that the small molecules are promising electron acceptors for non-fullerene organ

The energy loss in perovskite solar cells (PSCs) is a key factor that limits the full potential of photovoltaic performance to values below the Shockley–Queisser limit.

Two medium-bandgap polymers composed of benzo[1,2-b:4,5-b']dithiohpene and 2,1,3-benzothiadiazole with 6-octyl-thieno[3,2-b]thiophene as a π-bridge unit are synthesized and their photovoltaic properties are analyzed. The two polymers have deep highest occupied molecular orbital energy levels, high crystallinity, optimal bulk-heterojunction morphology, and efficient charge transport, resulting in a power conversion efficiency of as high as 9.44% for a single-junction polymer solar-cell device.

A graft copolymer, poly(styrene sulfonic acid) grafted with polyaniline (PSSA- g -PANI), is synthesized and used as the hole transport layer in polymer solar cells based on poly(3-hexylthiophene) and [6,6]-phenyl- C 61-butyric acid methyl ester. Electrochemical stability of PSSA- g -PANI is superior to poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), which has widely been used as the hole transport material in polymer solar cells. The unique high transparency in 450−650 nm wa

Abstract Polymer solar cells are fabricated by a novel solution coating process, roller painting. The roller‐painted film – composed of poly(3‐hexylthiophene) (P3HT) and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) – has a smoother surface than a spin‐coated film. Since the roller painting is accompanied by shear and normal stresses and is also a slow drying process, the process effectively induces crystallization of P3HT and PCBM. Both crystalline P3HT and PCBM in the roller‐painted active

A new building block for low band-gap polymers, diketopyrrolopyrrole (DPP) flanked by pyridine (PyDPP), has been synthesized via a simple synthetic route. PyDPP was polymerized with bithiophene (BT) to afford a low band-gap copolymer (PBTPyDPP) which was used as an electron donor of the active layer in polymer solar cells. The solar cell device based on PBTPyDPP exhibited a promising PCE of 4.9% with a high VOC over 0.9 V, which is one of the highest values among DPP-based polymer solar cells.