Ramon Orlando Valencia Maturana

Bio: Ramon Orlando Valencia Maturana is an academic researcher from Academia Sinica. The author has contributed to research in topics: Polymer solar cell & Organic solar cell. The author has an hindex of 1, co-authored 1 publications receiving 64 citations.

2-Alkyl-5-thienyl-Substituted Benzo[1,2-b:4,5-b′]dithiophene-Based Donor Molecules for Solution-Processed Organic Solar Cells

Abstract: In this study, we have strategically designed and convergently synthesized two novel, symmetrical, and linear A–D–A-type π-conjugated donor molecules (TBDTCNR, TBDTCN), each containing a planar electron-rich 2-octylthiene-5-yl-substituted benzodithiophene (TBDT) unit as the core, flanked by octylthiophene units and end-capped with electron-deficient cyanoacetate (CNR) or dicyanovinyl (CN) units. We thoroughly characterized both of these materials and investigated the effects of the end groups (CNR, CN) on their optical, electrochemical, morphological, and photovoltaic properties. We then fabricated solution-processed bulk heterojunction organic solar cells incorporating TBDTCNR and TBDTCN. Among our tested devices, the one containing TBDTCNR and [6,6]-phenyl-C61-butyric acid methyl ester in a 1:0.40 ratio (w/w) exhibited the highest power conversion efficiency (5.42%) with a short-circuit current density (Jsc) of 9.08 mA cm–2, an open circuit voltage (Voc) of 0.90 V, and an impressive fill factor (FF) of ...

Molecular Design of Benzodithiophene-Based Organic Photovoltaic Materials.

Abstract: Advances in the design and application of highly efficient conjugated polymers and small molecules over the past years have enabled the rapid progress in the development of organic photovoltaic (OPV) technology as a promising alternative to conventional solar cells. Among the numerous OPV materials, benzodithiophene (BDT)-based polymers and small molecules have come to the fore in achieving outstanding power conversion efficiency (PCE) and breaking 10% efficiency barrier in the single junction OPV devices. Remarkably, the OPV device featured by BDT-based polymer has recently demonstrated an impressive PCE of 11.21%, indicating the great potential of this class of materials in commercial photovoltaic applications. In this review, we offered an overview of the organic photovoltaic materials based on BDT from the aspects of backbones, functional groups, alkyl chains, and device performance, trying to provide a guideline about the structure-performance relationship. We believe more exciting BDT-based photovol...

Benzo[1,2-b:4,5-b′]dithiophene (BDT)-based small molecules for solution processed organic solar cells

Abstract: Solution processed small molecule based solar cells have become a competitive alternative to their polymer counterparts due to the advantages of their defined structure and thus less batch to batch variation. With a large and rigid planar conjugated structure, the benzo[1,2-b:4,5-b′]dithiophene (BDT) unit has become one of the most widely used and studied building blocks for high performance small molecule based photovoltaic devices. In this review article, we review the progress made in the field of small molecules containing BDT units for solution-processed organic photovoltaic cells. Insights into several important aspects regarding the design and synthesis of BDT based small molecules are also included.

High efficiency solution-processed two-dimensional small molecule organic solar cells obtained via low-temperature thermal annealing

Abstract: A new two-dimensional (2D) organic small molecule, DCA3T(T-BDT), was designed and synthesized for solution-processed organic solar cells (OSCs). DCA3T(T-BDT) exhibited a deep HOMO energy level (−5.37 eV) and good thermal stability. The morphologies of the DCA3T(T-BDT):[6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) blends were investigated by atomic force microscopy and the crystallinity was explored by X-ray diffraction (XRD) and 2D grazing incidence wide-angle X-ray scattering (GIWAXS), respectively. The morphologies of the blends were strongly influenced by the blend ratio of DCA3T(T-BDT):PC61BM and annealing temperature. The effect of thermal annealing on the photovoltaic performance of DCA3T(T-BDT)-based small molecule organic solar cells (SMOSCs) was studied in detail. When DCA3T(T-BDT) was used as a donor with PC61BM as an acceptor, high efficiency SMOSCs with a power conversion efficiency of 7.93%, a high Voc of 0.95 V, Jsc of 11.86 mA cm−2 and FF of 0.70 were obtained by a thermal annealing process at only 60 °C, which offers obvious advantages for large scale production compared with solvent additive or interfacial modification treatment.

Development of small-molecule materials for high-performance organic solar cells

Abstract: With the rapid development in recent years, small-molecule organic solar cell is challenging the dominance of its counterpart, polymer solar cell. The top power conversion efficiencies of both single and tandem solar cells based on small molecules have surpassed 9%. In this mini review, achievements of small molecules with impressive photovoltaic performance especially reported in the last two years were highlighted. The relationship between molecular structure and device performance was analyzed, which draws some rules for rational molecular design. Five series of p- and n-type small molecules were selected based on the consideration of their competitiveness of power conversion efficiencies.