21st of May
Illuminating the Future
The Physics of Photovoltaics

University of Groningen

Prof. Maria Loi

Event Host

Maria Antonietta Loi studied physics at the University of Cagliari in Italy where she received the PhD in 2001 for a thesis on Photoexcitations and Interchain Interactions in Conjugated Oligomers and Polymers which was carried out in the group of Prof. G. Bongiovanni and A. Mura. In the same year she joined the Linz Institute for Organic Solar cells, of the University of Linz, Austria as a postdoctoral fellow. Later she worked as researcher at the Institute for Nanostructured Materials of the Italian National Research Council in Bologna, Italy. In 2006 she became assistant professor and Rosalind Franklin Fellow at the Zernike Institute for Advanced Materials of the University of Groningen, The Netherlands. She is now full professor in the same institution and chair of the Photophysics and OptoElectronics group.

She has published more than 240 peer-reviewed articles on photophysics and optoelectronics of different types of materials. The main interest is unravelling the properties of novel semiconductors and to tune their properties to fabricate highly performing optoelectronic devices (Solar cells, LEDs, Photodetectros etc.)

University of Groningen

Prof. Jan Anton Koster

Jan Anton Koster

We use a combination of experimental and simulation techniques to identify how the performance of devices is related to the properties of the materials and basic physical processes. Our work focuses on functional materials that can be easily processed from solution. This means that using the materials to make a functional device requires little energy and is cheap.

Eindhoven University of Technology

Prof. Adriana Creatore

Plasma and Material Processing

Innovation in thin film and interface engineering has played an essential role in pushing the conversion efficiency of the most widespread photovoltaic (PV) technology, i.e. crystalline silicon-based (c-Si), towards its thermodynamic limit. In this respect, ultra-thin, conformal, high-purity Al₂O₃ thin films synthesized by ALD are key in c-Si PV manufacturing industry as they passivate the c-Si surface, thereby suppressing a major channel of electron-hole pair recombination. Recently, we have explored the ALD synthesis of thin films for metal halide perovskite- based photovoltaics. The latter has rapidly reached a conversion efficiency of 26% and, when coupled with c-Si PV in a so-called tandem device, leads to efficiencies already beyond 33%. In this contribution I will discuss the merits which ALD offers to perovskite-based PV by reviewing our work on NiO-based hole transport layers and discussing in depth the case study of ALD SnO 2 . The latter is implemented in perovskite PV R&D and industry as buffer layer, i.e., imparting thermal and environmental stability to the device, while protecting the perovskite absorber and fullerene electron transport layer from the sputtering of the transparent top contact. More recently, ALD SnO 2 is explored as solvent barrier layer in the tunnel recombination junction of perovskite/perovskite tandem PV, to prevent the damage of the wide-gap perovskite absorber when processing the narrow band-gap perovskite cell. Although we can conclude that several ALD merits are already extensively acknowledged by the PV community, studies addressing ALD film growth on challenging substrates such as fullerenes and metal halide perovskites are rarely reported in literature. We are convinced that these studies provide a rationale to implement more efficiently these layers at device level and promote process upscaling. Therefore, this contribution will also highlight the adoption of in situ diagnostics, namely spectroscopic ellipsometry and IR spectroscopy, to characterize the ALD SnO 2 growth on two commonly adopted fullerenes, C60 and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). Our studies show that a substrate-inhibited growth occurs in the case of PCBM and, to a minor extent, in the case of C60, with respect to the traditional c-Si substrate. Moreover, IR spectroscopy highlights the loss of vibrational features of the ester group in PCBM upon SnO 2 growth, whereas C60 is chemically unaffected. We conclude that the the delayed film growth and chemical modifications detected on PCBM are responsible for the consistently lower device performance when ALD SnO 2 is grown on PCBM instead of C60.

University of Twente

Suzana Kralj

Vacuum-deposited materials for emerging solar cells technologies

The current energy and climate challenges make the transition to a sustainable and renewable energy model increasingly necessary. Solar energy conversion through the development of efficient solar cells is a promising solution. As the materials used in solar cells play a crucial role in determining their performance, materials science, combining disciplines such as physics, chemistry and engineering, assumes a crucial position in driving advancements in this field.

In this talk, we will discuss the fundamental principles behind solar cells, exploring their structure, fabrication methods, key challenges, and ongoing research efforts aimed at addressing these challenges from a materials science point of view. We will highlight our latest advancements in the development of transparent electrodes and contact layers for solar cells and vacuum-deposited halide perovskites for application in photovoltaic technologies.

In the first part of the talk, we focus on the recent developments on transparent electrodes and contact layers for high efficiency solar cells. Specifically, we discuss how the microstructure of the transparent conductive oxide (TCO) impacts the electronic properties of hole selective contact layers for perovskite solar cells, using the case example of Sn-doped In 2 O 3 (ITO) and self-assembled monolayers (SAMs).

In the second part, we'll shift our attention to the growth of metal halide perovskites for solar cells, with a particular focus vacuum-based deposition of these perovskites. We'll discuss the potential of Pulsed Laser Deposition (PLD) as an alternative vacuum, vapor-based deposition technique for precisely tailoring complex metal halide perovskite thin films. We will also discuss recent development on the fabrication of perovskites by hybrid vacuum and solution processes. All this with the motivation of future application in perovskite-based tandem devices.

These advancements represent crucial steps towards controlling growth processes and ensuring the future scalability of materials used in efficient photovoltaic devices.

Director PV Industrialisation, CEA-INES, Bourget-du-Lac, France

Dr.Ir. Dick Heslinga

Renaissance of a PV manufacturing industry in Europe : living in momentous times

Transforming the steady progress in photovoltaics Research and Development into succesful industrial initiatives is of prime importance for the health of the sector in Europe, but over the last decade has proven extremely challenging. Ever increasingly, the mainstream of PV manufacturing worldwide is shaped by multi-GW scale, commodization, ultra-low cost, and a relentless pace of innovation. Yet, in face of these formidable barriers to entry, but recognizing the strategic imperative of energy sovereignity, this is the time that EU policy is shaping up to do ‘whatever it takes’ to favour the launching of a new generation of industrial PV manufacturing companies across the Si PV value chain. Taking a selective look at current innovation trends, the colloquium will identify promising technologies and industrial strategies. We will analyze the dynamics at work, the difficulties encountered, and the factors for success. Concrete cases of industrial initiatives will be placed in the broader EU policy context and in the specific strategy of the Netherlands via the ‘SolarNL’ Groeifonds programme. Will the renaissance succeed? Much to be done, much to be won.

PhotonDelta

Peter van Arkel

Applications of Integrated Photonics

Photonic Integrated Circuits (PICs) are revolutionizing optical devices in a similar way as the electronic IC has done for computing. Lasers, detectors, modulators and waveguides are all integrated into a single chip. This integration reduces cost, power consumption, size and weight. These advantages of PICs are game changers in applications like autonomous vehicles, healthcare, agrifood, datacenters and artificial intelligence.

In his talk Peter will take you on a journey through the evolution of PICs, the current applications, and future trends to contribute to more sustainable world.

Delmic

Herman Duim

Cathodoluminescence

Delmic is a passionate high-tech company based in Delft, Netherlands that develops powerful and user-friendly solutions for electron microscopy, bringing life science and material science researchers and organizations closer to research insights across diverse application fields.

Abstract talk by Herman Duim, application specialist for Cathodoluminescence at Delmic: Understanding the fundamental properties of materials is essential for the advancement of technology. In both academic and industrial research, characterization plays a pivotal role, especially in the study of photovoltaic materials. Cathodoluminescence imaging represents a sophisticated technique that merges electron microscopy with light microscopy, offering unique insights. This talk introduces the basic principles of cathodoluminescence spectroscopy and illustrates its practical application in photovoltaic research through relevant examples. Join us as we explore how this advanced imaging method contributes to a deeper understanding of photovoltaic materials.