My research is focussed towards understanding the charge and exciton dynamics of organic solar cells (OSCs) using time resolved optical spectroscopic tools. The goal is to obtain a detailed understanding of exciton dissociation, charger transfer and free charge generation steps in OSCs. I am also interested in exploring charge transfer at organic/inorganic hybrid interfaces through ultrafast transient absorption spectroscopy (TAS). I obtained my PhD at the University of Queensland for investigation on exitonic losses in organic lasers.
My research focuses on the analysis of energy losses in solar cells in terms of experimental, analytical, and simulation work. In addition, I work on optimzing optoelectronic characterization techniques for more precise characterization results.
Both the deployment and scale-up of perovskite solar cells imply a thorough understanding of the fundamental physical phenomena underlying light absorption, charge separation, carrier transport and energy generation of photovoltaic devices at a laboratory-scale. To achieve this goal, my research focuses on the development and characterisation of thin-film partial stacks and working devices by means of several techniques, namely, electroluminescence and photoluminescence spectroscopy, transient photovoltage and photocurrent measurements. These allow me to assess their loss-mechanisms and recombination channels, and thereby finding the path to the optimization towards the thermodynamic limits. Of my particular interest are the wide-bandgap single-junction perovskite solar cells with organic transport layers intended for tandem applications.
My research focusses on trying to get a better physical understanding of different perovskite systems. Currently, I am mainly looking into the effect of mobile ions and doping on device performance. In order to do this, I use a combination of experimental work and simulations.
My main affiliation is with the group of Prof. Snaith at the Oxford University, but I am currently visiting the PotsdamPero group.
Despite the exceptional progress of perovskite solar cells, the mechanism governing interfacial recombination is still in debate. A better and more fundamental approach is required to understand the states and pathways the recombination proceeds. To do that I am employed in the SURPRISE project which is about Understanding and suppressing Interfacial charge recombination for high-performance Perovskite Solar cells. My research aims to understand the role of interfacial energy alignment between the perovskite and transport layers and the physical nature of C60-induced interfacial traps. For this, I will use a range of complementary measurement techniques for example transient and steady-state photoluminescence as well as electro-optical transient measurement.
Since the dawn of non-fullerene acceptors (NFAs), there holds much promise for higher efficiency organic solar cells (OSCs). However, the excitonic nature of organic semiconductors means that OSCs still endure innate energy and photovoltage losses, since free charge carriers are formed and recombine via excitons at donor:acceptor interfaces. My research and interest lie in the intersection of these subjects. By using various transient and steady-state optoelectronic techniques, I aim to understand how the energetics and dynamics of the NFA singlet & interfacial excitons relate to the open-circuit voltage, and how they affect fundamental processes like the generation or recombination of free charge carriers in NFA-based OSCs.
I am originally from Ethiopia and completed my Bachelor and Master degrees at Adama Science and Technology University (ASTU) in Materials Science and Engineering.
Currently, Metal-halide perovskites are rapidly emerging as the next-generation space photovoltaic (PV) technology with radiation tolerance significantly higher than the Si and III-V technologies and powering space solar panels. However, Space environment poses a very different set of extremes such as radiation, ultraviolet photons, extreme temperatures and temperature cycles and atomic oxygen causing performance degradation of the solar cell devices in space. To solve these problems, my research focuses on the development and optimization of halide Perovskite based single and multijunction-photovoltaics which is followed by advanced characterization of their stability and degradation in extreme conditions.
I am a Ph.D. student in the (Radiation-) Tolerant Electronics with Soft Semiconductors (ROSI) Group within the Soft Matter Physics Group at the University of Potsdam. I earned both my bachelor's and master’s degrees in Chemistry at İzmir Institute of Technology. My research was focused on the design, synthesis, and characterization of colloidal carbon quantum dots and their applications during my master’s study. In addition, my research activities involved the synthesis and characterization of different shapes of colloidal plexcitonic nanocrystals with tunable optical properties in the visible region of the electromagnetic spectrum by using metal nanocrystals and different exciton sources. Currently, I am working on the Perovskite Single Crystal (PSC) based Radiation Detectors.
I am always fascinated by the light-matter interaction and physical phenomena behind it. I have studied on understanding and tune the structural, electronic, and optical properties of perovskites using both experimental methods and ab-initio simulations. Also, I studied graphene-based flexible photodetectors. Now, as a Ph.D. student, I am excited to move one step further and work on perovskite solar cells on ROSI Group and contribute to the development of renewable energy.
Guorui He works as a research student on the low-bandgap organic solar cells in the Soft Matter Physics Group at the University of Potsdam. He is currently in the master program of Polymer Science and obtained his bachelor of engineering at the South China University of Technology (SCUT) in China. During his master, his research mainly focused on the performance limiting factors and recombination processes in different low-bandgap systems. Currently, Guorui He is optimizing the organic solar cells based on low-bandgap systems and investigating the loss mechanisms of the devices. At the same time, he is trying to reduce the losses of the device performance parameters.
My research focuses on a better physical understanding of the different organic solar cell systems. I am currently investigating the morphology and charge generation of these systems and what effect this has on the performance of the systems. For this purpose, I am fabricating and experimentally analyzing these systems.
Despite the optoelectronic prospects and the ultrahigh PCE ~26 % which make metal halide perovskite an outstanding absorber material for next generation PV devices, the challenge of long-term operational stability as a result its ionic nature and the degradation experienced due to the exposure to oxygen, moisture and ion migration among others had contributed to the big obstacles it has encountered so far on its way to commercialization. As a master’s student from KIT, my research focuses on various 2D passivation interlayers with a view to improving the performance as well as the stability of triple cation perovskite solar cells.
I am a Bachelor student at the Technical University Berlin (TUB) studying Aerospace engineering. Through my studies, I gained interest in programming with Python, which led me to working with the PotsdamPero group. Currently, I am helping with developing FastChar - a Python program for testing solar cells.
I am a bachelor’s student studying physics at the University of Potsdam, and I am interested in the charge and exciton dynamics in organic solar cells. Currently, I am supporting Atul with the analysis of his transient absorption spectroscopy data, including analysis by the means of Multivariate Curve Resolution (MCR).