Publications by Wolfgang Richard Tress

Related publications (59)

When photoluminescence, electroluminescence, and open-circuit voltage diverge - light soaking and halide segregation in perovskite solar cells

Ulf Anders Hagfeldt, Wolfgang Richard Tress, Bowen Yang, Yeonju Kim

Perovskite solar cells suffer from various instabilities on all time scales. Some of them are driven by light, in particular when employing compounds with mixed halides. Such light soaking effects have been observed to result in performance changes of sola ...

Royal Society of Chemistry2021

Electroluminescence Dynamics in Perovskite Solar Cells Reveals Giant Overshoot Effect

Wolfgang Richard Tress, Marius Franckevicius

High performance of both photovoltaic and electroluminescent devices requires low nonradiative recombination losses. In perovskites, such loses strongly depend on the carrier traps related to the mobile ions and vacancies, causing I-V hysteresis of solar c ...

AMER CHEMICAL SOC2019

Intermediate Phase Enhances Inorganic Perovskite and Metal Oxide Interface for Efficient Photovoltaics

Michael Graetzel, Ulf Anders Hagfeldt, Dominik Józef Kubicki, Wolfgang Richard Tress, David Lyndon Emsley, Claudia Esther Avalos, Zaiwei Wang, Yuhang Liu, Anand Agarwalla, Brian Irving Carlsen, Aditya Mishra, Haizhou Lu

Interfacial modification is crucial to fully develop the potential of semiconductor devices, including the revolutionary halide perovskite-based optoelectronics, such as photovoltaics, light-emitting diodes, and photodetectors. The all-inorganic halide per ...

CELL PRESS2020

Addition of adamantylammonium iodide to hole transport layers enables highly efficient and electroluminescent perovskite solar cells

Michael Graetzel, Dominik Józef Kubicki, Wolfgang Richard Tress, David Lyndon Emsley, Jovana Milic

The efficiency of perovskite solar cells (PSCs) is currently limited by non-radiative recombination losses. One potential loss channel consists of electrons recombining at the interface with the hole transport layer (HTL). We synthesized adamantylammonium ...

ROYAL SOC CHEMISTRY2018

Unreacted PbI2 as a Double-Edged Sword for Enhancing the Performance of Perovskite Solar Cells

Jacques-Edouard Moser, Joël Teuscher, Kurt Schenk, Ulf Anders Hagfeldt, Marine Eva Fedora Bouduban, Wolfgang Richard Tress, Juan-Pablo Correa-Baena, Tor Jesper Jacobsson

Lead halide perovskites have over the past few years attracted considerable interest as photo absorbers in PV applications with record efficiencies now reaching 22%. It has recently been found that not only the composition but also the precise stoichiometr ...

American Chemical Society2016

How far does the defect tolerance of lead-halide perovskites range? The example of Bi impurities introducing efficient recombination centers

Björn Niesen, Simone Meloni, Wolfgang Richard Tress, Juan-Pablo Correa-Baena, Zaiwei Wang, Chien-Jen Yang

One of the key properties of lead-halide perovskites employed in solar cells is the defect tolerance of the materials, in particular regarding intrinsic point defects, which mainly form shallow traps. Considering that high luminescence yields and photovolt ...

Royal Society of Chemistry2019

Crystal-Size-Induced Band Gap Tuning in Perovskite Films

Michael Graetzel, Amita Ummadisingu, Simone Meloni, Wolfgang Richard Tress

A comprehensive picture explaining the effect of the crystal size in metal halide perovskite films on their opto-electronic characteristics is currently lacking. We report that perovskite nanocrystallites exhibit a wider band gap due to concurrent quantum ...

Wiley-VCH Verlag GmbH2021

Ionic polarization-induced current–voltage hysteresis in CH3NH3PbX3 perovskite solar cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Thomas Moehl, Peng Gao, Peng Gao, Yonghui Lee, Simone Meloni, Wolfgang Richard Tress, Marius Franckevicius, Michael Saliba

CH3NH3PbX3 (MAPbX(3)) perovskites have attracted considerable attention as absorber materials for solar light harvesting, reaching solar to power conversion efficiencies above 20%. In spite of the rapid evolution of the efficiencies, the understanding of b ...

Nature Research2016

Light Harvesting and Charge Recombination in CH3NH3PbI3 Perovskite Solar Cells Studied by Hole Transport Layer Thickness Variation

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Robin Humphry-Baker, Mohammad Ibrahim Dar, Nevena Vaskova Marinova, Wolfgang Richard Tress

A tailored optimization of perovskite solar cells requires a detailed understanding of the processes limiting the device efficiency. Here, we study the role of the hole transport layer (HTL) spiro-MeOTAD and its thickness in a mesoscopic TiO2-based solar c ...

American Chemical Society2015

Phosphonic Acid Modification of the Electron Selective Contact: Interfacial Effects in Perovskite Solar Cells

Ulf Anders Hagfeldt, Rebecca Hill, Wolfgang Richard Tress, Juan-Pablo Correa-Baena

The role electron-transport layers (ETLs) play in perovskite solar cells (PSCs) is still widely debated. Conduction band alignment at the perovskite/ETL interface has been suggested to be an important role for the performance of the solar cells. However, l ...

AMER CHEMICAL SOC2019

Formamidinium-Based Dion-Jacobson Layered Hybrid Perovskites: Structural Complexity and Optoelectronic Properties

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Ulf Anders Hagfeldt, Amita Ummadisingu, Mohammad Ibrahim Dar, Marko Mladenovic, Wolfgang Richard Tress, Farzaneh Jahanbakhshi, Paramvir Ahlawat, Brian Irving Carlsen, Yang Li, Jovana Milic, Algirdas Ducinskas

Layered hybrid perovskites have emerged as a promising alternative to stabilizing hybrid organic-inorganic perovskite materials, which are predominantly based on Ruddlesden-Popper structures. Formamidinium (FA)-based Dion-Jacobson perovskite analogs are de ...

2020

The effect of illumination on the formation of metal halide perovskite films

Michael Graetzel, Ludmilla Steier, Amita Ummadisingu, Wolfgang Richard Tress, Antonio Abate, Jiyoun Seo

Optimizing the morphology of metal halide perovskite films is an important way to improve the performance of solar cells(1) when these materials are used as light harvesters(2), because film homogeneity is correlated with photovoltaic performance(3). Many ...

Nature Publishing Group2017

Performance of perovskite solar cells under simulated temperature-illumination real-world operating conditions

Michael Graetzel, Ulf Anders Hagfeldt, Konrad Domanski, Wolfgang Richard Tress, Essa Awadh R Alharbi, Anand Agarwalla, Brian Irving Carlsen

Since reaching 20% efficiency, research in perovskite photovoltaics has shifted from a race for efficiency to a race for stability. For efficiency, the standard test conditions set the rules for the race. However, the term 'stability' is used very broadly ...

NATURE PUBLISHING GROUP2019

Review on Recent Progress of All-Inorganic Metal Halide Perovskites and Solar Cells

Wolfgang Richard Tress

All-inorganic perovskites are considered to be one of the most appealing research hotspots in the field of perovskite photovoltaics in the past 3 years due to their superior thermal stability compared to their organic-inorganic hybrid counterparts. The pow ...

Wiley-V C H Verlag Gmbh2019

New method for lateral mapping of bimolecular recombination in thin-film organic solar cells

Wolfgang Richard Tress

The best organic solar cells are limited by bimolecular recombination. Tools to study these losses are available; however, they are only developed for small area (laboratory-scale) devices and are not yet available for large area (production-scale) devices ...

Wiley-Blackwell2016

Highly efficient and stable planar perovskite solar cells by solution-processed tin oxide

Michael Graetzel, Ulf Anders Hagfeldt, Ludmilla Steier, Konrad Domanski, Wolfgang Richard Tress, Juan-Pablo Correa-Baena, Antonio Abate, Michael Saliba

Perovskite solar cells (PSCs) are one of the most promising lab-scale technologies to deliver inexpensive solar electricity. Low-temperature planar PSCs are particularly suited for large-scale manufacturing. Here, we propose a simple, solution-processed te ...

Royal Society of Chemistry2016

A charge carrier transport model for donor-acceptor blend layers

Wolfgang Richard Tress

Highly efficient organic solar cells typically comprise donor-acceptor blend layers facilitating effective splitting of excitons. However, the charge carrier mobility in the blends can be substantially smaller than in neat materials, hampering the device p ...

American Institute of Physics2015

Working Principles of Perovskite Photodetectors: Analyzing the Interplay Between Photoconductivity and Voltage-Driven Energy-Level Alignment

Michael Graetzel, Mohammad Khaja Nazeeruddin, Thomas Moehl, Konrad Domanski, Wolfgang Richard Tress, Michael Saliba

Organic-inorganic lead halide perovskites have recently received significant attention as active materials for high-performance photovoltaics and photo-detectors. However, the understanding of their operation mechanism remains limited. High-gain, low-volta ...

Wiley-V C H Verlag Gmbh2015

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

Michael Graetzel, Shaik Mohammed Zakeeruddin, Wolfgang Richard Tress, Michael Saliba

A series of novel polymers (P1P6) derived from the combination of different units (including thiophene, triarylamine, and spirobifluorene) were successfully synthesized, completely characterized, and used as hole-transporting materials (HTMs) for perovskit ...

American Chemical Society2019

How the formation of interfacial charge causes hysteresis in perovskite solar cells

Michael Graetzel, Ulf Anders Hagfeldt, Wolfgang Richard Tress

In this study, we discuss the underlying mechanism of the current-voltage hysteresis in a hybrid lead-halide perovskite solar cell. We have developed a method based on Kelvin probe force microscopy that enables mapping charge redistribution in an operating ...

ROYAL SOC CHEMISTRY2018