Open Access Published by De Gruyter Open Access

Volume 6 Issue 1

April 2018

Issue of Organic Photonics and Photovoltaics

Contents
Journal Overview

Open Access June 15, 2019

Recent Advances in Squaraine Dyes for Bulk-Heterojunction Organic Solar Cells

Yao Chen, Weigang Zhu, Jianglin Wu, Yan Huang, Antonio Facchetti, Tobin J. Marks

Page range: 1-16

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Abstract

Squaraine (SQ) dyes are an important class of electron-donating (donors or p-type) semiconductors for organic solar cells (OSC) due to their facile synthetic access, broad optical absorption with high oscillator strengths, and chemical robustness. Blending them with compatible electron-acceptors (acceptors or n-type) yields OSC devices known as bulk-heterojunction (BHJ) small molecule donor organic solar cells (SMD-OSCs). Through extensive research on materials design, synthesis, characterization, and device optimization over the past ˝ve years, SMD-OSCs employing SQ-based structures have achieved remarkable increases in device power conversion e˚ciency (PCE), now approaching 8%. Although these PCEs have not yet equaled the performance of state- of-the art donor polymers and some other SMD semiconductors, SQ-based OSC progress highlights successful and generalizable strategies for small molecule solar cells that should lead to future advances. In this review, recent developments in SQ-based OSCs are discussed and analyzed.

Open Access May 15, 2018

The effect of PbS nanocrystal additives on the charge transfer state recombination in a bulk heterojunction blend

Mustapha Abdu-Aguye, Loredana Protesescu, Dmitry N. Dirin, Maksym V. Kovalenko, Maria Antonietta Loi

Page range: 1-7

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Abstract

A persistent limitation of organic semiconductors is their low dielectric constant є r , which limits the performance of bulk heterojunction (BHJ) solar cells. One way to increase є r is to employ high-є r additives, such as PbS nanocrystals (QDs) to BHJ blends. In this work, we use the recombination of the interfacial charge transfer (CT) state as a means to study the effects of PbS nanocrystals on blends of a narrow bandgap copolymer: poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1- b;3,4-b′]dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT), and phenyl-C61-butyric acid methyl ester (PCBM). We show that at low dilution levels (0.25% - 0.75% by weight), there is a decrease in the relative weight of the CT recombination lifetime (longer decay component); suggesting that there is an increase in the local є r of the ternary blend.

Open Access December 31, 2018

Diketopyrrolopyrrole latent pigment-based bilayer solar cells

Luca Beverina, Myles Rooney, Riccardo Ruffo, Mauro Sassi, Francesco Carulli, Silvia Luzzati, Roland Resel, Benedikt Schrode

Page range: 8-16

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Abstract

Two Diketopyrrolopyrrole based latent pigment donor materials were fabricated into thin film bilayer photovoltaic devices featuring PCBM as the acceptor. Thermal deprotection of the thin film, carried out at 200∘ C, returns the dye-like small molecule to the corresponding pristine pigment quantitatively. The connected evolution of electrical and morphological features of pure thin films and blends are examined. A significant decrease in extinction coefficient was noted and correlated both to intrinsic changes of the electronic structure upon cleavage and to an increase in internal scattering due to extensive crystallization. Power conversion efficiencies of 0.33% were achieved for bilayer devices, nearly doubling previous results with latent pigment DPP devices, under comparable experimental conditions.

About this journal

The Organic Photonics and Photovoltaics (OPP) journal has been closed since the beginning of the 2019.

The journal covered topics of the most important advances in the chemistry, physics, materials science, and engineering of organic photo-active materials for primary applications in photovoltaic cells but extending other photonic devices involving the generation, propagation, detection, and processing of light. Papers The journal was published in Open Access model and is archived in Portico.

All authors retain copyright, unless – due to their local circumstances – their work is not copyrighted. The copyrights are governed by the Creative-Commons license.