Hae Jung Son

Herein, we describe the synthesis of fluorinated polythienothiophene-co-benzodithiophenes (PTBFs) and the characterization of their physical properties, especially their performance in solar cells. Fluorination of the polymer backbone lowered both the HOMO and LUMO energy levels and simultaneously widened the energy bandgap of the polymer (0.1-0.2 eV). Incorporation of fluorine into the various positions of the polymer backbone significantly affected the solar cells' power conversion efficiency

Organic solar cells based on bulk heterojunctions (BHJs) are attractive energy-conversion devices that can generate electricity from absorbed sunlight by dissociating excitons and collecting charge carriers. Recent breakthroughs attained by development of nonfullerene acceptors result in significant enhancement in power conversion efficiency (PCEs) exceeding 17%. However, most of researches have focused on pursuing high efficiency of small-area (<1 cm² ) unit cells fabricated usually

Conjugated polymers based on a heteroacene, 3,7-dialkyl-dithieno[2,3-d:2′,3′-d′]benzo[1,2-b:4,5-b′]dithiophene (DBD), are synthesized. These polymers show broad UV–vis absorption with energy bandgaps below 1.7 eV. PTDBD2, showing good miscibility in a polymer/phenyl-C71-butyric acid methyl ester (PC71BM) blend film, achieves a power conversion efficiency (PCE) of 7.6%. The results indicate that copolymers containing DBD are promising candidates for high-performance organic solar cells.

In this perspective article, we discuss the development of organic photovoltaic (OPVs) solar cells. Our focus will be on discussing the development of new donor polymers and device technologies, which resulted in enormous progress in OPV performances with power conversion efficiencies (PCEs) of 8–9%. However, for the wide spread usage of OPVs, high module efficiencies (>10%) and lifetimes suitable for commercial applications are required. To achieve such goals, interdisciplinary advances in the

Over the last ten years, polymer solar cells have been developed as an attractive alternative to the traditional silicon photovoltaic devices. Remarkable progress has been made in polymer-fullerene solar cells and several polymers have shown power conversion efficiencies (PCEs) greater than 7%. The most important recent development has been the synthesis of new low bandgap polymers with optimal properties for the solar cells. Herein we provide an overview of the key strategies of optimization of

We investigated the effects of chemical structures of non-fullerene acceptors on the photo-stability of polymer solar cells.

We report a new hole transporting material (HTM) based on [2,2]paracyclophane triarylamine. Due to its higher charge mobility compared with spiro-OMeTAD, the solar cell device incorporating the new HTM achieved a high photovoltaic performance with a PCE of 17.6%.

We synthesized a donor polymer of bis(2-ethylhexyl)thiophene-substituted benzodithiophene (BDT-Th) and 1,3-bis(2-ethylhexyl)-5,7-di(thiophene-2-yl)benzo[1,2-c:4,5-c′]dithiophene-4,8-dione, for which the BDT-Th unit includes chlorine and sulfur-bridged 2-ethylhexyl in the thiophene side group. When compared with PBDB-TF, which includes fluorine and 2-ethylhexyl in BDT-Th, PBDB-TSCl shows more efficient exciton dissociation and charge generation, which is probably because large dipole moment chang

Introduction of polyethyleneimine (PEI) onto the perovskite layer allows HTMs to strongly adhere to the perovskite layer, simultaneously enhancing moisture stability.

A series of hole-transporting materials (HTMs) based on [2,2]paracyclophane and triphenyl-amine (TPA) was synthesized. We studied the effect of the chemical structure of the HTM on the photovoltaic performance of perovskite solar cells by varying the number of TPA charge transporting components in the HTM. Tetra-TPA, in which four TPAs are incorporated into the [2,2]paracyclophane core, exhibited better hole transport properties than di-TPA and tri-TPA, which contain two and three TPAs, respecti

This article reviews the mechanisms of morphology evolution of bulk heterojunction (BHJ) films, recent research progress for morphology control of nonfullerene-based BHJs, and coating techniques for producing scalable BHJs.

Abstract For the commercial development of organic photovoltaics (OPVs), laboratory‐scale OPV technology must be translated to large area modules. In particular, it is important to develop high‐efficiency polymers that can form thick (&gt;100 nm) bulk heterojunction (BHJ) films over large areas with optimal morphologies for charge generation and transport. Here, D 1 ‐A‐D 2 ‐A random terpolymers composed of 2,2′‐bithiophene with various proportions of 5,6‐difluoro‐4,7‐bis(thiophen‐2‐yl)‐2,1,3‐ben

A dichlorobenzene-functionalized hole-transporting material (HTM) is developed for a CH3NH3PbI3-based perovskite solar cell. Notwithstanding the similarity of the frontier molecular orbital energy levels, optical properties, and hole mobility between the functionalized HTM [a polymer composed of 2'-butyloctyl-4,6-dibromo-3-fluorothieno[3,4-b]thiophene-2-carboxylate (TT-BO), 3',4'-dichlorobenzyl-4,6-dibromo-3-fluorothieno[3,4-b]thiophene-2-carboxylate (TT-DCB), and 2,6-bis(trimethyltin)-4,8-bis(2

Understanding the effects of the chemical structures of donor polymers on the photovoltaic properties of their corresponding organic photovoltaic (OPV) devices under various light-intensity conditions is important for improving the performance of these devices. We synthesized a series of copolymers based on poly[(2,6-(4,8-bis(5-(2-thioethylhexyl)thiophen-2-yl)benzo[1,2-<i>b</i>:4,5-<i>b</i>']dithiophene))-<i>alt</i>-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-<i>c</i>:4',5'-<i>c<

Abstract Donor–acceptor random copolymers incorporating 1,3‐bis(thiophen‐2‐yl)‐5,7‐bis(2‐ethylhexyl)benzo[1,2‐ c :4,5‐ c ′]dithiophene‐4,8‐dione (BDD) and 4,8‐bis(5‐(2‐ethylhexyl)thiophen‐2‐yl)benzo[1,2‐ b :4,5‐ b ′]dithiophene (BDT‐Th) are developed. Nonfullerene solar cells introducing the random copolymer PBDB‐T73 (BDT‐Th:BDD=7:3) and 3,9‐bis(2‐methylene‐(3‐(1,1‐dicyanomethylene)‐indanone))‐5,5,11,11‐tetrakis(4‐hexylphenyl)‐dithieno[2,3‐ d :2′,3′‐ d ′]‐s‐indaceno[1,2‐ b :5,6‐ b ′]dithiophene