Search results for: Stoichko D. Dimitrov

Items from 1 to 8 out of 8 results

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Multiphoton Absorption Stimulated Metal Chalcogenide Quantum Dot Solar Cells under Ambient and Concentrated Irradiance

Bo Hou, Byung‐Sung Kim, Harrison Ka Hin Lee, Yuljae Cho, more

Advanced Functional Materials > 30 > 39 > n/a - n/a

Colloidal metal chalcogenide quantum dots (QDs) have excellent quantum efficiency in light–matter interactions and good device stability. However, QDs have been brought to the forefront as viable building blocks in bottom‐up assembling semiconductor devices, the development of QD solar cell (QDSC) is still confronting considerable challenges compared to other QD technologies due to their low performance...

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Towards Efficient Integrated Perovskite/Organic Bulk Heterojunction Solar Cells: Interfacial Energetic Requirement to Reduce Charge Carrier Recombination Losses

Matyas Daboczi, Jinhyun Kim, Jinho Lee, Hongkyu Kang, more

Advanced Functional Materials > 30 > 25 > n/a - n/a

Integrated perovskite/organic bulk heterojunction (BHJ) solar cells have the potential to enhance the efficiency of perovskite solar cells by a simple one‐step deposition of an organic BHJ blend photoactive layer on top of the perovskite absorber. It is found that inverted structure integrated solar cells show significantly increased short‐circuit current (J_sc) gained from the complementary absorption...

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Influence of Blend Morphology and Energetics on Charge Separation and Recombination Dynamics in Organic Solar Cells Incorporating a Nonfullerene Acceptor

Hyojung Cha, Scot Wheeler, Sarah Holliday, Stoichko D. Dimitrov, more

Advanced Functional Materials > 28 > 3 > n/a - n/a

Nonfullerene acceptors (NFAs) in blends with highly crystalline donor polymers have been shown to yield particularly high device voltage outputs, but typically more modest quantum yields for photocurrent generation as well as often lower fill factors (FF). In this study, we employ transient optical and optoelectronic analysis to elucidate the factors determining device photocurrent and FF in blends...

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Photophysical Study of DPPTT‐T/PC₇₀BM Blends and Solar Devices as a Function of Fullerene Loading: An Insight into EQE Limitations of DPP‐Based Polymers

Elisa Collado‐Fregoso, Florent Deledalle, Hendrik Utzat, Pabitra S. Tuladhar, more

Advanced Functional Materials > 27 > 6 > n/a - n/a

Diketopyrrolopyrrole (DPP)‐based polymers have been consistently used for the fabrication of solar cell devices and transistors due to the existence of intermolecular short contacts, resulting in high electron and hole mobilities. However, they also often show limited external quantum efficiencies (EQEs). In this contribution, the authors analyze the limitations on EQE by a combined study of exciton...

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Thiazole Orange Dimers in DNA: Fluorescent Base Substitutions with Hybridization Readout

Sina Berndl, Stoichko D. Dimitrov, Florian Menacher, Torsten Fiebig, more

Chemistry – A European Journal > 22 > 7 > 2386 - 2395

By using (S)‐2‐amino‐1,3‐propanediol as a linker, thiazole orange (TO) was incorporated in a dimeric form into DNA. The green fluorescence (λ=530 nm) of the intrastrand TO dimer is quenched, whereas the interstrand TO dimer shows a characteristic redshifted orange emission (λ=585 nm). Steady‐state optical spectroscopic methods reveal that the TO dimer fluorescence is independent of the sequential...

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Thieno[3,2‐b]thiophene‐diketopyrrolopyrrole Containing Polymers for Inverted Solar Cells Devices with High Short Circuit Currents

Hugo Bronstein, Elisa Collado‐Fregoso, Afshin Hadipour, Ying W. Soon, more

Advanced Functional Materials > 23 > 45 > 5647 - 5654

The synthesis and characterization four diketopyrrolopyrrole containing conjugated polymers for use in organic photovoltaics is presented. Excellent energy level control is demonstrated through heteroatomic substitution whilst maintaining similar solid state properties as shown by X‐ray diffraction and atomic force microscopy. Inverted solar cells were fabricated with the best devices having short...