Publications de Valentin Ianis Emmanuel Queloz

Single-crystalline TiO2 nanoparticles for stable and efficient perovskite modules

Keith Gregory Brooks, Mohammad Khaja Nazeeruddin, Paul Joseph Dyson, Valentin Ianis Emmanuel Queloz, Wen Luo, Hiroyuki Kanda, Yen-Cheng Liu, Bin Ding, Yong Ding

The incorporation of electron transport layers based on single-crystalline TiO2 rhombohedral nanoparticles enables the realization of stable and efficient large-area perovskite solar cell modules. ...

Nature Portfolio2022

Revealing Weak Dimensional Confinement Effects in Excitonic Silver/Bismuth Double Perovskites

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Giulia Grancini, Pascal Alexander Schouwink, Inés Garcia Benito, Albertus Adrian Sutanto

Lead-free perovskites are attracting increasing interest as nontoxic materials for advanced optoelectronic applications. Here, we report on a family of silver/bismuth bromide double perovskites with lower dimensionality obtained by incorporating phenethyla ...

AMER CHEMICAL SOC2022

Phosphine Oxide Derivative as a Passivating Agent to Enhance the Performance of Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Mounir Driss Mensi, Valentin Ianis Emmanuel Queloz, Tom Theodorus Antonius Lummen, Aditya Gilra, Aron Joel Huckaba, Hiroyuki Kanda, Cansu Igci, Albertus Adrian Sutanto, Hobeom Kim

Defects of metal-halide perovskites detrimentally influence the optoelectronic properties of the thin film and, ultimately, the photovoltaic performance of perovskite solar cells (PSCs). Especially, defect-mediated nonradiative recombination that occurs at ...

2021

Beyond Tolerance Factor: Using Deep Learning for Prediction Formability of ABX3 Perovskite Structures

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Tom Theodorus Antonius Lummen, Alexander Fedorovskiy

Deep learning (DL) is a modern powerful instrument for multiple purposes, including classification. In this study, this technique is applied to the task of perovskites formability. A commonly known perovskite dataset is used to try to make an instrument su ...

2021

Isomeric Carbazole-Based Hole-Transporting Materials: Role of the Linkage Position on the Photovoltaic Performance of Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Cansu Igci, Albertus Adrian Sutanto

Two structural isomers of carbazole decorated with triarylamine have been designed and synthesized with a facile synthetic procedure. The impact of triarylamine substitution on the isomeric structural linkage of carbazole on the optical, thermal, electroch ...

AMER CHEMICAL SOC2021

Two-Step Thermal Annealing: An Effective Route for 15 % Efficient Quasi-2D Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Giulia Grancini, Albertus Adrian Sutanto, Giorgio Schileo, Valentino Romano

Low-dimensional perovskites (LDP) are nowadays recognized as promising materials for the realization of highly performing photovoltaic cells. However, issues related to film morphology, composition, crystal quality and material homogeneity limit the device ...

WILEY-V C H VERLAG GMBH2021

Photoinduced processes in hybrid perovskite for optoelectronics

Valentin Ianis Emmanuel Queloz

Hybrids organic-inorganic perovskite(HOP) solar cells have unequivocally the potential for being a new generation of solar panels with a lower cost and a greater efficiency than well-known silicon solar panels. Today, even if HOPs are seen as one of the be ...

EPFL2021

Stable Perovskite Solar Cells Using Molecularly Engineered Functionalized Oligothiophenes as Low-Cost Hole-Transporting Materials

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Hiroyuki Kanda, Cansu Igci, Albertus Adrian Sutanto

Triarylamine-substituted bithiophene (BT-4D), terthiophene (TT-4D), and quarterthiophene (QT-4D) small molecules are synthesized and used as low-cost hole-transporting materials (HTMs) for perovskite solar cells (PSCs). The optoelectronic, electrochemical, ...

WILEY-V C H VERLAG GMBH2021

Fluorination of Organic Spacer Impacts on the Structural and Optical Response of 2D Perovskites

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Tom Theodorus Antonius Lummen, Giulia Grancini, Inés Garcia Benito, Pietro Caprioglio

Low-dimensional hybrid perovskites have triggered significant research interest due to their intrinsically tunable optoelectronic properties and technologically relevant material stability. In particular, the role of the organic spacer on the inherent stru ...

2020

Exploring the role of halide mixing in lead-free BZA(2)SnX(4) two dimensional hybrid perovskites

Valentin Ianis Emmanuel Queloz, Giulia Grancini

The role of halide substitution in a lead-free 2D hybrid perovskite is investigated on the BZA(2)SnX(4) (BZA = benzylammonium; X = Cl, Br and I) system, by reporting the synthesis and the structural analysis by means of single-crystal X-ray diffraction dat ...

Royal Society of Chemistry2020

An Efficient Approach to Fabricate Air-Stable Perovskite Solar Cells via Addition of a Self-Polymerizing Ionic Liquid

Mohammad Khaja Nazeeruddin, Rosario Scopelliti, Paul Joseph Dyson, Zhaofu Fei, Valentin Ianis Emmanuel Queloz, Farzaneh Fadaei Tirani, Tom Theodorus Antonius Lummen, Cristina Roldán Carmona, Nikita Drigo, Yi Zhang, Zhangjun Huang, Rui Xia

Despite the excellent photovoltaic properties achieved by perovskite solar cells at the laboratory scale, hybrid perovskites decompose in the presence of air, especially at high temperatures and in humid environments. Consequently, high-efficiency perovski ...

Wiley2020

Green-Emitting Lead-Free Cs4SnBr6 Zero-Dimensional Perovskite Nanocrystals with Improved Air Stability

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Tom Theodorus Antonius Lummen, Giulia Grancini

We report the synthesis and characterization of nanocrystals of a novel fully inorganic lead-free zero-dimensional perovskite, Cs4SnBr6. Samples are made of crystals with an average size of similar to 20 nm with green emission centered around 530 nm. Inter ...

2020

In Situ Analysis Reveals the Role of 2D Perovskite in Preventing Thermal-Induced Degradation in 2D/3D Perovskite Interfaces

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Nikita Drigo, Giulia Grancini, Albertus Adrian Sutanto, Rodrigo Szostak

Engineering 2D/3D perovskite interfaces is a common route to realizing efficient and stable perovskite solar cells. Whereas 2D perovskite’s main function in trap passivation has been identified and is confirmed here, little is known about its 2D/3D interfa ...

American Chemical Society (ACS)2020

Band-bending induced passivation: high performance and stable perovskite solar cells using a perhydropoly(silazane) precursor

Mohammad Khaja Nazeeruddin, Mounir Driss Mensi, Valentin Ianis Emmanuel Queloz, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Cristina Roldán Carmona, Aron Joel Huckaba, Giulia Grancini, Yi Zhang, Hiroyuki Kanda, Nadja Isabelle Desiree Klipfel, Mo Li

Surface passivation of the perovskite photo absorber is a key factor to improve the photovoltaic performance. So far robust passivation strategies have not yet been revealed. Here, we demonstrate a successful passivation strategy which controls the Fermi-l ...

2020

Spatial Charge Separation as the Origin of Anomalous Stark Effect in Fluorous 2D Hybrid Perovskites

Jacques-Edouard Moser, Mohammad Khaja Nazeeruddin, Marine Eva Fedora Bouduban, Valentin Ianis Emmanuel Queloz, Giulia Grancini, Inés Garcia Benito, Alexander Fedorovskiy

2D hybrid perovskites (2DP) are versatile materials, whose electronic and optical properties can be tuned through the nature of the organic cations (even when those are seemingly electronically inert). Here, it is demonstrated that fluorination of the orga ...

2020

Self-Crystallized Multifunctional 2D Perovskite for Efficient and Stable Perovskite Solar Cells

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Yonghui Lee, Kyung Taek Cho, Sanghyun Paek, Aron Joel Huckaba, Albertus Adrian Sutanto, Hobeom Kim

Recently, perovskite solar cells (PSC) with high power-conversion efficiency (PCE) and long-term stability have been achieved by employing 2D perovskite layers on 3D perovskite light absorbers. However, in-depth studies on the material and the interface be ...

WILEY-V C H VERLAG GMBH2020

Dynamical evolution of the 2D/3D interface: a hidden driver behind perovskite solar cell instability

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Kyung Taek Cho, Sanghyun Paek, Nikita Drigo, Giulia Grancini, Pascal Alexander Schouwink, Inés Garcia Benito, Albertus Adrian Sutanto

Engineering two-/three-dimensional (2D/3D) perovskite solar cells is nowadays a popular strategy for efficient and stable devices. However, the exact function of the 2D/3D interface in controlling the long-term device behavior is still obscure. Here, we re ...

Royal Society of Chemistry2020

Copper sulfide nanoparticles as hole-transporting-material in a fully-inorganic blocking layers n-i-p perovskite solar cells: Application and working insights

Mohammad Khaja Nazeeruddin, Valentin Ianis Emmanuel Queloz, Cristina Roldán Carmona, Giulia Grancini

One of the challenges in the field of perovskite solar cells (PSC) is the development of inorganic hole-transporting-materials (HTM) suitable for solution-processed deposition, in order to have cheaper, more stable and scalable devices. Herein, we report t ...

2019

Crystal Orientation Drives the Interface Physics at Two/Three-Dimensional Hybrid Perovskites

Jacques-Edouard Moser, Mohammad Khaja Nazeeruddin, Marine Eva Fedora Bouduban, Valentin Ianis Emmanuel Queloz, Kyung Taek Cho, Sanghyun Paek, Cristina Roldán Carmona, Giulia Grancini

Combining halide perovskites with tailored dimensionality into two/three-dimensional (2D/3D) systems has revealed a powerful strategy to boost the performances of perovskite photovoltaics (PVs). Despite recent advances, a clear understanding of the intimat ...

2019

Perovskite Solar Cells: 18% Efficiency Using Zn(II) and Cu(II) Octakis(diarylamine)phthalocyanines as Hole-Transporting Materials

Mohammad Khaja Nazeeruddin, Kasparas Rakstys, Valentin Ianis Emmanuel Queloz, Kyung Taek Cho, Marius Franckevicius, Sanghyun Paek, Hiroyuki Kanda

Metallophthalocyanines (MPcs) are currently emerging as alternative hole-transporting materials (HTMs) in perovskite solar cells (PSCs). However, the lack of systematic structure/photovoltaic properties investigations still hampers the rational design of M ...

2019