Explicit Pre A*-algebra

This manuscript is a study on Birkhoff centre of a Pre-A*-algebra. In fact, it is proved that Birkhoff centre of a Pre A*-algebra is also a Pre A*-algebra and identified that the centre of Birkhoff centre of a Pre A*-algebra is a Boolean algebra.Keywords: Pre A*-algebra, Centre, Birkoff centre, Boolean algebra

NIR absorbing D-pi-A-pi-D structured diketopyrrolopyrrole-dithiafulvalene based small molecule for solution processed organic solar cells

A new low band gap small molecule DPP-DTF with a D-pi-A-pi-D molecular structure composed of a dithiafulvalene (DTF) donor and a diketopyrrolopyrrole (DPP) acceptor was synthesized and tested for organic solar cells. Using the DPP-DTF small molecule as an electron donor, and PC71BM as an acceptor a high power conversion efficiency (PCE) of 4.3% was achieved

Organic Dyes Containing Carbazole as Donor and π‑Linker: Optical, Electrochemical, and Photovoltaic Properties

A series of new metal free organic dyes containing carbazole as donor and π-linker have been synthesized and characterized as effective sensitizers for dye sensitized solar cells (DSSCs). The carbazole functionalized at C-2 and C-7 served as electron-rich bridge. The donor property of the carbazole is substantially enhanced on introduction of <i>tert</i>-butyl groups at C-3 and C-6 positions and the oxidation propensity of the dyes increased on insertion of thiophene unit in the conjugation pathway. These structural modifications fine-tuned the optical and electrochemical properties of the dyes. Additionally, the presence of <i>tert</i>-butyl groups on the carbazole nucleus minimized the intermolecular interactions which benefited the performance of DSSCs. The dyes served as efficient sensitizers in DSSCs owing to their promising optical and electrochemical properties. The efficiency of DSSCs utilizing these dyes as sensitizers ranged from 4.22 to 6.04%. The <i>tert</i>-butyl groups were found to suppress the recombination of injected electrons which contributed to the increment in the photocurrent generation (<i>J</i>_SC) and open circuit voltage (<i>V</i>_OC). A dye with carbazole donor functionalized with <i>tert</i>-butyl groups and the conjugation bridge composed of 2,7-disubstituted carbazole and thiophene fragments exhibited higher <i>V</i>_OC value. However, the best device efficiency was observed for a dye with unsubstituted carbazole donor and the π-linker featuring carbazole and bithiophene units due to the high photocurrent generation arising from the facile injection of photogenerated electrons into the conduction band of titanium dioxide (TiO₂) facilitated by the low-lying LUMO

Highly Directional 1D Supramolecular Assembly of New Diketopyrrolopyrrole-Based Gel for Organic Solar Cell Applications

A new thermoreversible organogel based on diketopyrrolopyrrole dye (DPP-NCO) is reported for the first time and evolved as a new building block for the fabrication of 1D supramolecular assembly. AFM analysis illustrated that its gel state is composed of different sized 1D rods. DPP-NCO gel used as an additive in organic solar cells yields high efficiency of 7.9% owing to better nanophase separation of its active layer

Highly Directional 1D Supramolecular Assembly of New Diketopyrrolopyrrole-Based Gel for Organic Solar Cell Applications

A new thermoreversible organogel based on diketopyrrolopyrrole dye (DPP-NCO) is reported for the first time and evolved as a new building block for the fabrication of 1D supramolecular assembly. AFM analysis illustrated that its gel state is composed of different sized 1D rods. DPP-NCO gel used as an additive in organic solar cells yields high efficiency of 7.9% owing to better nanophase separation of its active layer