Publications by Paul Gratia | EPFL Graph Search

Nanoscale Mass-Spectrometry Imaging of Grain Boundaries in Perovskite Semiconductors

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Hiroyuki Kanda, Paul Gratia, Tom Theodorus Antonius Lummen

Incorporation of alkali metals such as Cs+, Rb+, and K+ into hybrid organic-inorganic halide lead perovskites (HOIPs) generally improves the optoelectronic properties of HOIPs. However, it is still uncertain how alkali metals interact and distribute within ...

2020

Improved efficiency and reduced hysteresis in ultra-stable fully printable mesoscopic perovskite solar cells through incorporation of CuSCN into the perovskite layer

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Giulia Grancini, Paul Gratia

Fully printable hole transport layer-free mesoscopic perovskite solar cells have proven excellent long-term stability and are therefore promising candidates for scale-up to larger modules required for the commercialization of the perovskite photovoltaic te ...

Royal Society of Chemistry2019

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

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

2018

Compositional Characterization of Organo-Lead tri-Halide Perovskite Solar Cells

Paul Gratia

Perovskite photovoltaics is one of the fastest growing research fields in materials science. Apart from photovoltaics, a wide range of energy-related research fields have gained substan-tial new momentum owing to the fantastic optoelectronic properties of ...

EPFL2018

Molecularly Engineered Phthalocyanines as Hole-Transporting Materials in Perovskite Solar Cells Reaching Power Conversion Efficiency of 17.5%

Mohammad Khaja Nazeeruddin, Giulia Grancini, Paul Gratia, Peng Gao, Kyung Taek Cho, Cristina Roldán Carmona, Olga Trukhina

Easily accessible tetra-5-hexylthiophene-, tetra-5-hexyl-2,2'-bisthiophene-substituted zinc phthalocyanines (ZnPcs) and tetra-tert-Bu ZnPc are employed as hole-transporting materials in mixed-ion perovskite [HC(NH2)2]0.85(CH3NH3)0.15Pb(I0.8 ...

2017

High-Efficiency Perovskite Solar Cells Using Molecularly Engineered, Thiophene-Rich, Hole-Transporting Materials: Influence of Alkyl Chain Length on Power Conversion Efficiency

Mohammad Khaja Nazeeruddin, Iwan Zimmermann, Giulia Grancini, Paul Gratia, Javier Urieta Mora

The synthesis and characterization of a series of novel small-molecule holetransporting materials (HTMs) based on an anthra [1,2-b: 4,3-b': 5,6-b '': 8,7-b '''] tetrathiophene (ATT) core are reported. The new compounds follow an easy synthetic route and ha ...

Wiley-V C H Verlag Gmbh2017

The Many Faces of Mixed Ion Perovskites: Unraveling and Understanding the Crystallization Process

Mohammad Khaja Nazeeruddin, Kevin Sivula, Jun Ho Yum, Paul Gratia, Iwan Zimmermann

Understanding the crystallization process of organic-inorganic halide perovskites is of paramount importance for fabrication of reproducible and efficient perovskite solar cells. We report for the first time on the discovery and interplay of ubiquitous hex ...

Amer Chemical Soc2017

Dopant-Free Hole-Transporting Materials for Stable and Efficient Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Christian Ludwig, Emad Oveisi, Peng Gao, Sanghyun Paek, Yonghui Lee, Kyung Taek Cho, Kasparas Rakstys, Paul Gratia, Peng Qin

Molecularly engineered novel dopant-free hole-transporting materials for perovskite solar cells (PSCs) combined with mixed-perovskite (FAPbI(3))(0.85)(MAPbBr(3))(0.15) (MA: CH3NH3+, FA: NH=CHNH3+) that exhibit an excellent power conversion efficiency of 18 ...

Wiley-V C H Verlag Gmbh2017

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

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

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

Charge transporting material for optoelectronic and/or photoelectrochemical devices

Michael Graetzel, Mohammad Khaja Nazeeruddin, Paul Gratia, Iwan Zimmermann, Inés Garcia Benito

The present invention relates to an optoelectronic and/or photoelectrochemical device comprising at least one organic-inorganic perovskite as sensitizer and at least one compound of formula (I) comprising one benzotrithiophene core Q, wherein each thiophen ...

2017