LMPV Symposium

LMPV Symposium 2022

At this symposium on June 17 we discuss the latest developments in light management for solar cells and related topics. The program consists of four talks by international keynote speakers, and covers investigations of methods and materials to ultimately go beyond the efficiency of conventional solar cells. This symposium is intended for everyone in solar cell research and provides a broad overview of the most exciting directions in photovoltaic light management.

This years’ LMPV symposium meeting is a live conference only; there will be no parallel online presentations. We will make the talks available online after the workshop.

Registration for the workshop is free of charge. We look forward to welcoming you on June 17.

Click here for more info on our LMPV research.

Keynote speakers

• Anna Fontcuberta i Morral (EPFL)
  Zinc phosphide as an earth abundant absorber for solar cells
• Bob van der Zwaan (University of Amsterdam)
  Solar energy from an energy and climate scenario perspective
• Prashant Kamat (Univ. Notre Dame, IN, USA)
  Directing the flow of energy and electrons in halide perovskite-molecular hybrids: energy versus electron transfer
  
• Patricia Schulze (Fraunhofer ISE)
  Monolithic 2-terminal perovskite silicon tandem solar cells

 

 

 

 

Anna Fontcuberta i Morral

Zinc phosphide as an earth abundant absorber for solar cells

Large-scale deployment of solar cells can only be achieved by using materials made of earth-abundant elements. Among the direct-bandgap earth abundant absorbers, zinc phosphide exhibits the highest potential. In this talk we will explain three different paths to achieving high quality zinc phosphide, circumventing all challenges due to the mismatch of its structure and coefficient of thermal expansion to any available commercial substrate. The solutions proposed are translatable to other systems and thus applicable to ‘materials discovery’ approaches.

Laboratory of Semiconductor Materials, EPFL, Lausanne

Bob van der Zwaan

Solar energy from an energy and climate scenario perspective

In this lecture the role of solar energy in global climate change mitigation is presented from both a technology assessment and integrated energy system modeling perspective. Integrated Assessment Models (IAMs) constitute an important tool in the work by the Intergovernmental Panel on Climate Change (IPCC). Most IPCC scenarios report a massive expansion of photovoltaics as one of the leading options to implement deep reductions in CO2 emissions before 2050. Current multi-disciplinary and techno-economic research focuses on whether solar energy can play an even larger role by extending its application beyond that in the generation and direct use of electricity.

¹ TNO, Energy Transition department (ETS), Amsterdam, The Netherlands

² University of Amsterdam, Faculty of Science (HIMS and IAS), Amsterdam, The Netherlands

³ Johns Hopkins University, School of Advanced International Studies (SAIS), Bologna, Italy

Prashant Kamat

Directing the flow of energy and electrons in halide perovskite-molecular hybrids: energy versus electron transfer

The flow of energy and electron transfer processes in semiconductor nanocrystal based light harvesting assemblies is dictated by the nature of the excited state interactions. Halide perovskite nanocrystals such as CsPbBr3 with relatively high emission yield and strong light absorption can transfer singlet and triplet energy to surface bound acceptor molecules. They can also induce photocatalytic reduction and oxidation by selectively transferring electrons and holes across the nanocrystal interface. Surface interactions of chromophore or redox active molecule which dictate the efficiency of energy/electron transfer thus plays an important role in realizing their photocatalytic and optoelectronic applications. The excited state interactions in the CsPbBr3-Rhodamine B (RhB) hybrid assembly and the electron transfer between CsPbBr3 and surface bound viologen will be discussed. These examples show how CsPbBr3 nanocrystals manage the flow of energy and electrons based on their interactions with the surface bound molecule.

Radiation Laboratory, Departments of Chemistry & Biochemistry and Chemical & Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556

Patricia Schulze

Monolithic 2-terminal perovskite silicon tandem solar cells

To enable terawatt-scale photovoltaics, resource and cost efficiency are mandatory. Perovskite silicon tandem solar cells can achieve both goals by exceeding the efficiency limit of 29.4% of single junction silicon solar cells, with only little additional production costs. We aim for monolithic 2-terminal tandem devices to facilitate module integration and to avoid parasitic absorption in laterally conductive layers.

Starting from a p-i-n perovskite top solar cell with a 1.68 eV absorber on p-type heterojunction silicon bottom solar cells with a pyramidal rear side texture and a planar front, we elaborate optimization steps to maximize the photocurrents in the sub-cells and achieve current matching. Supported by optical simulation using transfer matrix formalism, main process adaptions are addressed, e.g. development of a more transparent front contact layer and fine-tuning the perovskite band gap. Spectral metric analysis – comprising a systematic variation of the illumination spectrum, while keeping the overall irradiance constant – is applied to access the individual sub-cell´s current generation and confirm current matching. A certified current density of 19.6 mA/cm2 is achieved for optimized tandem devices with planar front. For further current increase and higher energy yield, fully textured tandem devices are needed. For this purpose, we investigate the dry/wet hybrid (evaporation and wet processing) route to allow perovskite deposition with tuneable band gap on µm-sized silicon texture.
Read more: full abstract (pdf)

Fraunhofer Institute for Solar Energy Systems ISE, Freiburg, Germany