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Kasparas Rakstys

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Related publications (35)

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Diphenylamine-Substituted Carbazole-Based Hole Transporting Materials for Perovskite Solar Cells: Influence of Isomeric Derivatives

Mohammad Khaja Nazeeruddin, Sanghyun Paek, Kyung Taek Cho, Kasparas Rakstys, Paul Gratia

2018

Molecular engineering of face-on oriented dopant-free hole transporting material for perovskite solar cells with 19% PCE

Mohammad Khaja Nazeeruddin, Peng Gao, Sanghyun Paek, Giulia Grancini, Kyung Taek Cho, Kasparas Rakstys, Paul Gratia

Through judicious molecular engineering, novel dopant-free star-shaped D-pi-A type hole transporting materials coded KR355, KR321, and KR353 were systematically designed, synthesized and characterized. KR321 has been revealed to form a particular face-on o ...

Royal Society of Chemistry2017

Zn(II) and Cu(II) tetrakis(diarylamine)phthalocyanines as hole-transporting materials for perovskite solar cells

Mohammad Khaja Nazeeruddin, Hiroyuki Kanda, Kasparas Rakstys, Jianxing Xia, Maria Cristina Momblona Rincón, Cansu Igci, Nadja Isabelle Desiree Klipfel

Finding new hole-transporting materials (HTMs) suitable for replacing the state-of-the-art spiro-OMe-TAD is still challenging. In this work, newly synthesized diarylamine-substituted metal phthalocyanines (MPcs, M 1/4 Zn(II) or Cu(II)) functionalized with ...

ELSEVIER SCI LTD2022

Cut from the Same Cloth: Enamine-Derived Spirobifluorenes as Hole Transporters for Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Kasparas Rakstys, Bin Ding, Albertus Adrian Sutanto, Maria Cristina Momblona Rincón, Cansu Igci

To attain commercial viability, perovskite solar cells (PSCs) have to be reasonably priced, highly efficient, and stable for a long period of time. Although a new record of a certified power conversion efficiency (PCE) value over 25% was achieved, PSC perf ...

AMER CHEMICAL SOC2021

A highly hindered bithiophene-functionalized dispiro-oxepine derivative as an efficient hole transporting material for perovskite solar cells

Mohammad Khaja Nazeeruddin, Peng Gao, Sanghyun Paek, Yonghui Lee, Kyung Taek Cho, Kasparas Rakstys, Paul Gratia

Dimethoxydiphenylamine-substituted dispiro-oxepine derivative 2,2',7,7'-tetrakis-(N,N'-di-4-methoxyphenylamine)dispiro-[fluorene-9,4'-dithieno(3,2-c:2',3'-e]oxepine-6',9 ''-fluorene] (DDOF) has been designed and synthesized using a facile synthetic route. ...

Royal Society of Chemistry2016

Triazatruxene-Based Hole Transporting Materials for Highly Efficient Perovskite Solar Cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Peng Gao, Mohammad Ibrahim Dar, Antonio Abate, Peng Gao, Gwénolé Jean Jacopin, Kasparas Rakstys

Four center symmetrical star-shaped hole transporting materials (HTMs) comprising planar triazatruxene core and electron-rich methoxy-engineered side arms have been synthesized and successfully employed in (FAPbI(3))(0.85)(MAPbBr(3))(0.15) perovskite solar ...

Amer Chemical Soc2015

Dopant‐Free Hole Transport Materials Afford Efficient and Stable Inorganic Perovskite Solar Cells and Modules

Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Hiroyuki Kanda, Kasparas Rakstys, Bin Ding, Yong Ding, Cansu Igci, Xianfu Zhang, Olga Syzgantseva

The emerging CsPbI3 perovskites are highly efficient and thermally stable materials for wide-band gap perovskite solar cells (PSCs), but the doped hole transport materials (HTMs) accelerate the undesirable phase transition of CsPbI3 in ambient. Herein, a d ...

Wiley-VCH Verlag GmbH2021

Blue-Coloured Highly Efficient Dye-Sensitized Solar Cells by Implementing the Diketopyrrolopyrrole Chromophore

Michael Graetzel, Mohammad Khaja Nazeeruddin, Jun Ho Yum, Thomas Moehl, Kasparas Rakstys, Joël Teuscher, Thomas Wesley Holcombe

The paradigm shift in dye sensitized solar cells (DSCs) - towards donor-pi bridge-acceptor (D-pi-A) dyes - increases the performances of DSCs and challenges established design principles. Framed by this shifting landscape, a series of four diketopyrrolopyr ...

Nature Publishing Group2013

Carbazole-based enamine: Low-cost and efficient hole transporting material for perovskite solar cells

Mohammad Khaja Nazeeruddin, Sanghyun Paek, Kyung Taek Cho, Kasparas Rakstys

A simple carbazole-based conjugated enamine V950 was synthesized, fully characterized and incorporated into a perovskite solar cell, which displayed high power conversion efficiency close to 18%. The investigated hole transporting material was synthesize ...

Elsevier Science Bv2017

Hole transport material for electrochemical or optoelectronic devices

Michael Graetzel, Mohammad Khaja Nazeeruddin, Kasparas Rakstys

ES 2575511 A1 20160629 • The present invention relates to novel compds., methods of prepg. the compds. and uses of the compds. as hole transport materials in optoelectronic devices or electrochem., and methods of producing devices. ...

2016

In-situ cross-linkable hole transporting triazatruxene monomers for optoelectronic devicestr

Mohammad Khaja Nazeeruddin, Tom Theodorus Antonius Lummen, Kasparas Rakstys, Aron Joel Huckaba

The invention discloses a polymerizable triazatruxene-based compound of formula (I), an optoelectronic and/or photoelectrochemical device comprising said compound of formula (I) as hole transporting material in hole transport layer under the form of a poly ...

2019

Dispiro-oxepine/thiapine derivatives for optoelectronic semiconductors

Mohammad Khaja Nazeeruddin, Sanghyun Paek, Kasparas Rakstys

The dispiro-oxepine/dispiro-thiapine derivatives for optoelectronic semiconductors is a compound based on a structure having a functionalized dispiro compound of formula (Ia) or (Ib) with the core unit being a seven-membered heterocycle oxepine or thiapine ...

2018

Branched Methoxydiphenylamine-Substituted Carbazole Derivatives for Efficient Perovskite Solar Cells: Bigger Is Not Always Better

Mohammad Khaja Nazeeruddin, Yi Zhang, Hiroyuki Kanda, Kasparas Rakstys, Jianxing Xia

A set of novel branched molecules bearing a different number of 3,6-bis(4,4'-dimethoxydiphenylamino)carbazole-based (CzOMeDPA) periphery arms linked together by aliphatic chains have been developed, and their performance has been tested in perovskite solar ...

AMER CHEMICAL SOC2021

Towards high-performance DPP-based sensitizers for DSC applications

Michael Graetzel, Mohammad Khaja Nazeeruddin, Jun Ho Yum, Kasparas Rakstys, Thomas Wesley Holcombe

A novel, asymmetric DPP bridge/core was synthesized and tested in DSC devices. By desymmetrising the DPP core/bridge, a remarkable IPCE of >80% and a maximum power conversion efficiency of 7.7% were achieved. With the use of a wide-bandgap co-sensitizer, 8 ...

Royal Society of Chemistry2012

A structural study of DPP-based sensitizers for DSC applications

Michael Graetzel, Mohammad Khaja Nazeeruddin, Jun Ho Yum, Peng Gao, Peng Gao, Davide Di Censo, Kasparas Rakstys, Magdalena Anna Marszalek, Thomas Wesley Holcombe

Four D-pi-A sensitizers comprising a thienyl-diketopyrrolopyrrole (ThDPP) bridge were synthesized and tested in iodide/triiodide liquid electrolyte DSC devices. The dye series was strategically designed to develop a structure-property relationship. The bes ...

Royal Society of Chemistry2012