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Wolfgang Richard Tress

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Related publications (70)

Understanding the Limit and Potential in Emerging Perovskite Solar Cells

Michael Graetzel, Wolfgang Richard Tress

In this contribution we give an overview of the recent development of metal-halide perovskite solar cells. We focus on the mixed electronic-ionic conductivity of this material, which causes hysteresis in the current-voltage curve. We discuss latest results ...

Ieee2017

Identifying and suppressing interfacial recombination to achieve high open-circuit voltage in perovskite solar cells

Michael Graetzel, Ulf Anders Hagfeldt, Konrad Domanski, Wolfgang Richard Tress, Juan-Pablo Correa-Baena, Antonio Abate, Michael Saliba, Elham Halvani Anaraki, Silver Hamill Turren Cruz

With close to 100% internal quantum efficiency over the absorption spectrum, photocurrents in perovskite solar cells (PSCs) are at their practical limits. It is therefore imperative to improve open-circuit voltages (VOC) in order to go beyond the current 1 ...

Royal Society of Chemistry2017

Perovskite Solar Cells on the Way to Their Radiative Efficiency Limit - Insights Into a Success Story of High Open-Circuit Voltage and Low Recombination

Wolfgang Richard Tress

Inorganic-organic lead-halide perovskite solar cells have reached efficiencies above 22% within a few years of research. Achieved photovoltages of >1.2 V are outstanding for a material with a bandgap of 1.6 eV - in particular considering that it is solutio ...

Wiley-V C H Verlag Gmbh2017

Globularity-Selected Large Molecules for a New Generation of Multication Perovskites

Michael Graetzel, Ulf Anders Hagfeldt, Wolfgang Richard Tress, Juan-Pablo Correa-Baena, Antonio Abate, Michael Saliba, Filippo de Angelis, Silver Hamill Turren Cruz

Perovskite solar cells (PSCs) use perovskites with an APbX(3) structure, where A is a monovalent cation and X is a halide such as Cl, Br, and/or I. Currently, the cations for high-efficiency PSCs are Rb, Cs, methylammonium (MA), and/or formamidinium (FA). ...

Wiley-Blackwell2017

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, Taisuke Matsui

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

The rapid evolution of highly efficient perovskite solar cells

Michael Graetzel, Ulf Anders Hagfeldt, Wolfgang Richard Tress, Juan-Pablo Correa-Baena, Antonio Abate, Michael Saliba, Tor Jesper Jacobsson

Perovskite solar cells (PSCs) have attracted much attention because of their rapid rise to 22% efficiencies. Here, we review the rapid evolution of PSCs as they enter a new phase that could revolutionize the photovoltaic industry. In particular, we describ ...

Royal Society of Chemistry2017

Migration of cations induces reversible performance losses over day/night cycling in perovskite solar cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Ulf Anders Hagfeldt, Konrad Domanski, Wolfgang Richard Tress, Juan-Pablo Correa-Baena, Antonio Abate, Taisuke Matsui, Michael Saliba, Filippo de Angelis, Silver Hamill Turren Cruz

Perovskites have been demonstrated in solar cells with a power conversion efficiency of well above 20%, which makes them one of the strongest contenders for next generation photovoltaics. While there are no concerns about their efficiency, very little is ...

Royal Soc Chemistry2017

Changes from Bulk to Surface Recombination Mechanisms between Pristine and Cycled Perovskite Solar Cells

Ulf Anders Hagfeldt, Wolfgang Richard Tress, Juan-Pablo Correa-Baena, Silver Hamill Turren Cruz

Several aspects on the photophysical characterization of lead halide hybrid organic inorganic perovskite solar cells remain unsolved. It has been observed that ionic transport and polarization of the interfaces cause very slow changes that interfere with t ...

Amer Chemical Soc2017

Metal Halide Perovskites as Mixed Electronic-Ionic Conductors: Challenges and Opportunities-From Hysteresis to Memristivity

Wolfgang Richard Tress

Metal halide perovskites are promising candidates for many classes of different optoelectronic devices. Apart from being a semiconductor, they additionally show ionic conductivity. It expresses itself in slow response times, reversible degradation, and hys ...

Amer Chemical Soc2017

Photovoltaic and Amplified Spontaneous Emission Studies of High-Quality Formamidinium Lead Bromide Perovskite Films

Benoît Marie Joseph Deveaud, Mohammad Khaja Nazeeruddin, Thomas Moehl, Mahmoud Saeed Qaid Mohammad Hezam, Peng Gao, Gwénolé Jean Jacopin, Mohammad Ibrahim Dar, Wolfgang Richard Tress, Neha Arora

This study demonstrates the formation of extremely smooth and uniform formamidinium lead bromide (CH(NH2)(2)PbBr3 = FAPbBr(3)) films using an optimum mixture of dimethyl sulfoxide and N,N-dimethylformamide solvents. Surface morphology and phase purity of t ...

Wiley-Blackwell2016

Extended Intermolecular Interactions Governing Photocurrent-Voltage Relations in Ternary Organic Solar Cells

Ursula Röthlisberger, Beatrice Beyer, Negar Ashari Astani, Simone Meloni, Wolfgang Richard Tress, Feng Gao

Efficient organic solar cells are based on (electron) donor-acceptor heterojunctions. An optically generated excited molecular state (exciton) is dissociated at this junction, forming a charge-transfer (CT) state in an intermediate step before the electron ...

2016

Inverted Current-Voltage Hysteresis in Mixed Perovskite Solar Cells: Polarization, Energy Barriers, and Defect Recombination

Michael Graetzel, Wolfgang Richard Tress, Antonio Abate, Michael Saliba

Organic-inorganic metal halide perovskite solar cells show hysteresis in their current-voltage curve measured at a certain voltage sweep rate. Coinciding with a slow transient current response, the hysteresis is attributed to a slow voltage-driven (ionic) ...

Wiley-VCH Verlag Berlin2016

Room Temperature as a Goldilocks Environment for CH3NH3PbI3 Perovskite Solar Cells: The Importance of Temperature on Device Performance

Ulf Anders Hagfeldt, Wolfgang Richard Tress, Juan-Pablo Correa-Baena, Tor Jesper Jacobsson

Terrestrial applications of solar cells during day-night cycling as well as operation in winter and summer involve substantial temperature variations, which influence the photophysics as well as the charge separation and transport properties in the various ...

American Chemical Society2016

Cesium-containing triple cation perovskite solar cells: improved stability, reproducibility and high efficiency

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Konrad Domanski, Wolfgang Richard Tress, Juan-Pablo Correa-Baena, Antonio Abate, Jiyoun Seo, Taisuke Matsui, Michael Saliba

Today's best perovskite solar cells use a mixture of formamidinium and methylammonium as the monovalent cations. With the addition of inorganic cesium, the resulting triple cation perovskite compositions are thermally more stable, contain less phase impuri ...

Royal Society of Chemistry2016

Band structure engineering in organic semiconductors

Beatrice Beyer, Wolfgang Richard Tress, Feng Gao

A key breakthrough in modern electronics was the introduction of band structure engineering, the design of almost arbitrary electronic potential structures by alloying different semiconductors to continuously tune the band gap and band-edge energies. Imple ...

American Association for the Advancement of Science2016

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, Taisuke Matsui, Michael Saliba, Elham Halvani Anaraki

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

Unbroken Perovskite: Interplay of Morphology, Electro-optical Properties, and Ionic Movement

Michael Graetzel, Ulf Anders Hagfeldt, Konrad Domanski, Wolfgang Richard Tress, Juan-Pablo Correa-Baena, Antonio Abate, Taisuke Matsui, Michael Saliba, Tor Jesper Jacobsson

Hybrid organic-inorganic perovskite materials have risen up as leading components for light-harvesting applications. However, to date many questions are still open concerning the operation of perovskite solar cells (PSCs). A systematic analysis of the inte ...

Wiley-V C H Verlag Gmbh2016

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, Elham Halvani Anaraki

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

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

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, 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

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