Publications by Wolfgang Richard Tress

Double Layer Composite Electrode Strategy for Efficient Perovskite Solar Cells with Excellent Reverse-Bias Stability (vol 15, 12, 2022)

Michael Graetzel, Chenyi Yi, Wolfgang Richard Tress

2023

Copolymer-Templated Nickel Oxide for High-Efficiency Mesoscopic Perovskite Solar Cells in Inverted Architecture

Michael Graetzel, Ulf Anders Hagfeldt, Wolfgang Richard Tress, Marco Alejandro Ruiz Preciado, Hong Zhang

Despite the outstanding role of mesoscopic structures on the efficiency and stability of perovskite solar cells (PSCs) in the regular (n-i-p) architecture, mesoscopic PSCs in inverted (p-i-n) architecture have rarely been reported. Herein, an efficient and ...

WILEY-V C H VERLAG GMBH2021

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

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

Transient Photovoltage Measurements on Perovskite Solar Cells with Varied Defect Concentrations and Inhomogeneous Recombination Rates

Wolfgang Richard Tress, Zaiwei Wang, Brian Irving Carlsen, Firouzeh Ebadi Garjan

In all kinds of solar cells, transient photovoltage (TPV) decay measurements have been used to determine charge carrier lifetimes and to quantify recombination processes and orders. However, in particular, for thin-film devices with a high capacitance, the ...

2020

Consensus statement for stability assessment and reporting for perovskite photovoltaics based on ISOS procedures

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Ulf Anders Hagfeldt, Henry Snaith, Konrad Domanski, Wolfgang Richard Tress, Antonio Abate, Michael Saliba, Monica Marcela Lira Cantu, Haibing Xie, Kai Zhu

Improving the long-term stability of perovskite solar cells is critical to the deployment of this technology. Despite the great emphasis laid on stability-related investigations, publications lack consistency in experimental procedures and parameters repor ...

NATURE PUBLISHING GROUP2020

Outstanding Passivation Effect by a Mixed-Salt Interlayer with Internal Interactions in Perovskite Solar Cells

Ulf Anders Hagfeldt, Wolfgang Richard Tress, Filippo de Angelis, Hui-Seon Kim, Bowen Yang, Jiajia Suo

Nonradiative recombination is a major limiting factor in obtaining efficient metal-halide perovskite photovoltaics. Here, a passivation treatment is developed by applying a mixture of a new ammonium salt, CF3(CF2)(2)CH2NH3I (HBAI), and a conventional forma ...

AMER CHEMICAL SOC2020

Vapor-assisted deposition of highly efficient, stable black-phase FAPbI(3) perovskite solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Ursula Röthlisberger, Ulf Anders Hagfeldt, Xiong Li, Wolfgang Richard Tress, David Lyndon Emsley, Paramvir Ahlawat, Claudia Esther Avalos, Zaiwei Wang, Yuhang Liu, Anand Agarwalla, Brian Irving Carlsen, Fan Fu, Aditya Mishra, Haizhou Lu, Felix Thomas Eickemeyer, Xianfu Zhang, Likai Zheng, Ying Yang

Mixtures of cations or halides with FAPbI(3) (where FA is formamidinium) lead to high efficiency in perovskite solar cells (PSCs) but also to blue-shifted absorption and long-term stability issues caused by loss of volatile methylammonium (MA) and phase se ...

American Association for the Advancement of Science2020

Highly efficient, stable and hysteresis-less planar perovskite solar cell based on chemical bath treated Zn2SnO4 electron transport layer

Michael Graetzel, Ulf Anders Hagfeldt, Wolfgang Richard Tress, Zaiwei Wang, Mohammad Mahdi Tavakoli, Seckin Akin, Faranak Sadegh, Marco Alejandro Ruiz Preciado

The electron transport layer (ETL) is a key constituent in perovskite solar cells (PSCs). It should provide efficient and selective electron extraction, low resistivity and high stability. Here, zinc stannate (Zn2SnO4, ZSO) is employed as an ETL in planar ...

Elsevier2020

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, Wanchun Xiang, Mona Shasti, Jiahuan Zhang, Aditya Mishra, Haizhou Lu, Ziyun Wang

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

Unravelling the structural complexity and photophysical properties of adamantyl-based layered hybrid perovskites

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, Yang Li, Algirdas Ducinskas

Layered hybrid perovskites comprising adamantyl spacer (A) cations based on the A(2)FA(n-1)Pb(n)I(3n+1)(n= 1-3, FA = formamidinium) compositions have recently been shown to act as promising materials for photovoltaic applications. While the corresponding p ...

Royal Society of Chemistry2020

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, Yang Li, 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

A partially-planarised hole-transporting quart-p-phenylene for perovskite solar cells

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

Herein, we describe the synthesis of a hole transporting material based on a partially planarised quart-p-phenylene core incorporating tetraketal and diphenylamine substituents that show optimal energy levels and solubility for perovskite solar cell applic ...

Royal Society of Chemistry2019

Perovskite Solar Cells Yielding Reproducible Photovoltage of 1.20 V

Michael Graetzel, Shaik Mohammed Zakeeruddin, Mohammad Ibrahim Dar, Wolfgang Richard Tress, Neha Arora, Essa Awadh R Alharbi, Pankaj Kumar Yadav

High photovoltages and power conversion efficiencies of perovskite solar cells (PSCs) can be realized by controlling the undesired nonradiative charge carrier recombination. Here, we introduce a judicious amount of guanidinium iodide into mixed-cation and ...

2019

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

Ba-induced phase segregation and band gap reduction in mixed-halide inorganic perovskite solar cells

Michael Graetzel, Ulf Anders Hagfeldt, Dominik Józef Kubicki, Wolfgang Richard Tress, Jingshan Luo, David Lyndon Emsley, Albert Hofstetter, Xiaoyan Wang, Zaiwei Wang, Wanchun Xiang, Jiahuan Zhang, Xiaoyu Wang

All-inorganic metal halide perovskites are showing promising development towards efficient long-term stable materials and solar cells. Element doping, especially on the lead site, has been proved to be a useful strategy to obtain the desired film quality a ...

Nature Research2019

Origin of apparent light-enhanced and negative capacitance in perovskite solar cells

Ulf Anders Hagfeldt, Wolfgang Richard Tress, Firouzeh Ebadi Garjan

So-called negative capacitance seems to remain an obscure feature in the analysis of the frequency-dependent impedance of perovskite solar cells. It belongs to one of the puzzling peculiarities arising from the mixed ionic-electronic conductivity of this c ...

Springer2019

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

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, Silver Hamill Turren Cruz

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

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

Wolfgang Richard Tress, Wanchun Xiang

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