Disordered Semiconductors

The semiconductor industry has long been dominated by inorganic materials, but organic semiconductors offer new possibilities with their customizable electronic properties, mechanical flexibility, and environmentally friendly nature. These materials enable applications beyond the reach of traditional semiconductors, paving the way for sustainable electronics and spintronics. However, major challenges in organic semiconductor technologies include their inherent disorder and stability, both of which constrain performance and scalability. Addressing these issues requires an interdisciplinary approach that combines advanced fabrication techniques with novel characterization methods.

This CReA focuses on bringing order to disordered organic semiconductors by leveraging epitaxial growth technique. Additionally, it will use advanced spectroscopic tools to gain deeper understanding into the remaining unresolved questions. Key objectives include:

• Developing epitaxial organic photoactive layers using molecular beam epitaxy (MBE) to control disorder-related limitations in organic solar cells.
• Device physics of organic and hybrid solar cells.
• Fundamental electrical, spectroscopic and structural studies of molecular electronic materials with numerical modelling and device studies, with the aim of optimizing the performance and stability of single junction and tandem solar cells based on molecular and hybrid materials.
• Probing dark spin states, to understand spin-transport, spin-generation and spin-detection at room temperature to explore their potential for spintronics.
• Advancing experimental and modeling tools to clarify the fundamental structure-property relationships in organic semiconductors.

We are interested in advancing scientific understanding of the charge and spin transport as well as the photophysics of organic semiconductors and low-temperature processible hybrid organic-inorganic semiconductors. By bridging the gap between organic and inorganic semiconductor research, this work opens new possibilities for high-performance optoelectronic and spintronic devices. The ability to fabricate highly ordered organic semiconductors could lead to more efficient solar cells, and novel hybrid materials. Furthermore, gaining insights into spin properties at room temperature brings us closer to practical spintronic applications. Ultimately, this research contributes to the development of transformative, sustainable technologies that address global challenges in energy (mitigation potential of solar photovoltaic technology) and information processing.

• Leibniz: Sinfonia
• EU MSCA: OPVStability
• Pushing the FF of Non-Fullerene Acceptors Based Solar Cells Above 80%: Relating Order to Reduced Recombination to Device Performance (Fabulous II)

2024

1. Contemporary Impedance Analyses of Archetypical PM6: Y6 Bulk‐Heterojunction Blend
   Authors: N. Tokmoldin, C. Deibel, D. Neher, S. Shoaee
   Source: Adv. Energy Mater., 14, 2401130 (2024)
   DOI: 10.1002/aenm.202401130
    
2. Key factors behind the superior performance of polymer-based NFA blends
   Authors: E. Sağlamkaya, M. S. Shadabroo, N. Tokmoldin, T. M. Melody, B. Sun, O. Alqahtani, A. Patterson, B. A. Collins, D. Neher, S. Shoaee
   Source: Mater. Horiz., 11, 5304-5312 (2024)
   DOI: 10.1039/D4MH00747F

2023

1. Toward more efficient organic solar cells: a detailed study of loss pathway and its impact on overall device performance in Low‐Offset organic solar cells
   Authors: Bowen Sun, Nurlan Tokmoldin, Obaid Alqahtani, Acacia Patterson, Catherine S. P. De Castro, Drew B. Riley, Manasi Pranav, Ardalan Armin, Frédéric Laquai, Brian A. Collins, Dieter Neher, Safa Shoaee
   Source: Advanced Energy Materials 13 (26), 2300980
   DOI: https://doi.org/10.1002/aenm.202300980
    
2. Self‐Doping of the Transport Layers Decreases the Bimolecular Recombination by Reducing Static Disorder
   Authors: Elifnaz Sağlamkaya, Seyed Mehrdad Hosseini, Nurlan Tokmoldin, Artem Musiienko, Thomas Krüger, Jan Behrends, Meysam Raoufi, Dieter Neher, Safa Shoaee
   Source: Solar RRL 7 (19), 2300423
   DOI: https://doi.org/10.1002/solr.202300423
    
3. Elucidating how low energy offset matters to performance of nonfullerene acceptor-based solar cells
   Authors: Nurlan Tokmoldin, Bowen Sun, Floriana Moruzzi, Acacia Patterson, Obaid Alqahtani, Rong Wang, Brian A Collins, Iain McCulloch, Larry Lüer, Christoph J Brabec, Dieter Neher, Safa Shoaee
   Source: ACS Energy Letters 8 (6), 2552-2560
   DOI: https://doi.org/10.1021/acsenergylett.3c00572
    
4. Relationship between Energetic Disorder and Reduced Recombination of Free Carriers in Organic Solar Cells
   Authors: Seyed Mehrdad Hosseini, Sebastian Wilken, Bowen Sun, Fei Huang, Sang Young Jeong, Han Young Woo, Veaceslav Coropceanu, Safa Shoaee
   Source: Advanced Energy Materials 13 (8), 2203576
   DOI: https://doi.org/10.1002/aenm.202203576
    
5. What is special about Y6; the working mechanism of neat Y6 organic solar cells
   Authors: Elifnaz Sağlamkaya, Artem Musiienko, Mohammad Saeed Shadabroo, Bowen Sun, Sreelakshmi Chandrabose, Oleksandra Shargaieva, Niek F van Hulst, Safa Shoaee
   Source: Materials Horizons 10 (5), 1825-1834
   DOI: https://doi.org/10.1039/D2MH01411D
    
6. Molecularly induced order promotes charge separation through delocalized charge-transfer states at donor–acceptor heterojunctions
   Authors: Xiangkun Jia, Lorenzo Soprani, Giacomo Londi, Seyed Mehrdad Hosseini, Felix Talnack, Stefan Mannsfeld, Safa Shoaee, Dieter Neher, Sebastian Reineke, Luca Muccioli, Gabriele D’Avino, Koen Vandewal, David Beljonne, Donato Spoltore
   Source: Materials Horizons 11 (1), 173-183
   DOI: 10.1039/D3MH00526G
    
7. What we have learnt from PM6:Y6
   Authors: S. Shoaee, H. M. Luong, J. Song, Y. Zou, T.-Q. Nguyen, D. Neher
   Source: Adv. Mater., 36, 2302005 (2023)
   DOI: 10.1002/adma.202302005