Tailored Crystallization Dynamics for Efficient and Stable DMSO-Free Tin Perovskite Solar Cells Shengnan Zuo, Alexander Tarasov, Lennart Frohloff, Karunanantharajah Prashanthan, Florian Ruske, et al. Advanced Science, 2025 Tin perovskite solar cells are emerging as a sustainable lead‐free alternative in thin film photovoltaics. DMSO‐free processed tin perovskites are gaining interest due to the detrimental effects of DMSO on tin oxidation. However, replacing DMSO with other solvents remains challenging due to the accelerated crystallization dynamics in non‐DMSO systems. In this study, the crystallization process in a DMSO‐free solvent system is regulated by managing the transition from the sol‐gel phase to the solid film. Specifically, piperazine dihydriodide (PDAI) and 4‐tert‐butylpyridine (tBP) are utilized to coordinately tune the colloidal chemistry through forming large pre‐nucleation clusters in perovskite ink, further, facilitating the film formation process. By combining tBP and PDAI, a controllable crystallization rate is achieved as evidenced by in situ photoluminescence (PL) measurement during spin‐coating. As a result, tin perovskite films show high crystallinity and improved microstructure. Devices treated with tBP+PDAI exhibit a champion power conversion efficiency of 7.8% and excellent stability without observable degradation for over 3000 h stored in the N2 glovebox. These findings advance understanding and managing crystallization in DMSO‐free solvents processed tin perovskite solar cells.
Phenothiazine-Based Self-Assembled Monolayer with Thiophene Head Groups Minimizes Buried Interface Losses in Tin Perovskite Solar Cells Valerio Stacchini, Madineh Rastgoo, Mantas Marčinskas, Chiara Frasca, Kazuki Morita, et al. Advanced Energy Materials, 2025 Self‐assembled monolayers (SAMs) have revolutionized the fabrication of lead‐based perovskite solar cells, but they still remain underexplored in tin perovskite systems. To date, PEDOT remains the most effective hole‐selective layer in tin perovskite solar cells (TPSCs), yet it presents challenges for both performance and stability. MeO‐2PACz, the only SAM reported for tin perovskites consistently underperforms when compared to PEDOT. In this work, it is identified that MeO‐2PACz's limitations stem from excessively strong interactions with the perovskite surface and poor lattice matching, which leads to inferior interface quality. To address these issues, a novel SAM‐forming molecule called Th‐2EPT is designed, synthesized, and characterized. Density functional theory (DFT) is used to evaluate coordination strength and lattice compatibility, complemented by electro‐optical characterisation techniques that show significantly reduced interfacial recombination and improve material crystallinity in Th‐2EPT/Perovskite films. With Th‐2EPT, the first SAM‐based tin perovskite solar cells that outperform PEDOT‐based devices, delivering a power conversion efficiency (PCE) of 8.2% with a DMSO‐free solvent system, are demonstrated.
Texture-Enhanced Mechanical Stability of Transparent Electrodes for Flexible Optoelectronics with Near-Infrared Response Simon Rieckhoff, Florian Riesebeck, Marcos Soldera, Katja Mayer‐Stillrich, Qiong Wang, et al. Advanced Materials Interfaces, 2025 Transparent electrodes with high conductivity and mechanical robustness are essential for flexible opto‐electronic applications. Indium tin oxide (ITO) single layers have long been considered as unsuitable for flexible applications due to their brittleness. Here, it is shown that their mechanical stability can be substantially enhanced by texturing the flexible substrate. First, the opto‐electronic performance of single ITO layers and ITO/Ag/ITO stacks on polyethylene terephthalate (PET) foils is evaluated numerically by means of Haacke's figure‐of‐merit. Single ITO layers are found to be the electrode of choice for applications with a near‐infrared response due to their superior transparency. Following this, the sheet resistance of ITO layers is experimentally investigated on textured PET upon deformation parallel and perpendicular to a 1D texture grating. An “accordion‐like” deformation perpendicular to the grating and high texture aspect ratios are shown to avoid crack formation and loss of conductivity in the ITO. Simulations prove the considerably reduced occurrence of mechanical stress in this case. It is further experimentally demonstrated that texturing foils increase transmittance and haze. The enhanced mechanical robustness and optical performance by using textured foils make single ITO layers promising candidates for flexible opto‐electronic applications with a near‐infrared response, such as all‐perovskite tandem solar cells, thermal sensors, and photodetectors.
Description of excitonic absorption using the Sommerfeld enhancement factor and band-fluctuations K Lizárraga, E Serquen, P Llontop, L A Enrique, M Piñeiro, et al. Journal of Physics D Applied Physics, 2025 One of the challenges of excitonic materials is the accurate determination of the exciton binding energy and bandgap from optical measurements. The difficulty arises from the overlap of the discrete and continuous excitonic absorption at the band edge. Many researches have modeled the shape of the absorption edge of such materials on the seminal formulation proposed by Elliott in 1957 (Phys. Rev. 108 1384–9) and its several modifications such as non-parabolic bands, magnetic potentials and electron–hole-polaron interactions. However, exciton binding energies obtained from optical absorption often vary strongly depending on the chosen ‘Elliott formula’. Here, we propose an alternative and rather simple approach, which has previously been successful in the determination of the optical bandgap of amorphous, direct and indirect semiconductors, based on the band-fluctuations (BFs) model. In this model, the fluctuations due to disorder, temperature or lattice vibrations give rise to the well known exponential shape of band tail states. The formulation results in an analytic equation for the fundamental absorption with 6 parameters only. To test it, the binding energy and optical bandgap of GaAs and the family of tri-halide perovskites ( MAPbX 3 ), X = Br , I , Cl , over a wide range of temperatures, are obtained by fitting the modified Elliott model. The results for the bandgap, linewidth and exciton binding energy are in good agreement with reports based on non-optical measurements. Moreover, due to the polar nature of perovskites, the retrieved binding energies can be compared with those computed with a model proposed by Kane (1978 Phys. Rev. B 18 6849). In the latter model, the exciton is surrounded by a cloud of virtual phonons interacting via the Frölich interaction. As a consequence, the upper bound for the binding energy of the exciton-polaron system can be estimated. These results are in good agreement with the optical parameters obtained with the proposed Elliott equation including BFs.
Transient grating spectroscopy on a DyCo5 thin film with femtosecond extreme ultraviolet pulses Victor Ukleev, Ludmila Leroy, Riccardo Mincigrucci, Dario De Angelis, Danny Fainozzi, et al. Structural Dynamics, 2024 Surface acoustic waves (SAWs) are excited by femtosecond extreme ultraviolet (EUV) transient gratings (TGs) in a room-temperature ferrimagnetic DyCo5 alloy. TGs are generated by crossing a pair of EUV pulses from a free electron laser with the wavelength of 20.8 nm matching the Co M-edge, resulting in a SAW wavelength of Λ = 44 nm. Using the pump-probe transient grating scheme in reflection geometry, the excited SAWs could be followed in the time range of −10 to 100 ps in the thin film. Coherent generation of TGs by ultrafast EUV pulses allows to excite SAW in any material and to investigate their couplings to other dynamics, such as spin waves and orbital dynamics. In contrast, we encountered challenges in detecting electronic and magnetic signals, potentially due to the dominance of the larger SAW signal and the weakened reflection signal from underlying layers. A potential solution for the latter challenge involves employing soft x-ray probes, albeit introducing additional complexities associated with the required grazing incidence geometry.
ZnO:Al films for a-Si:H thin film solar cells Proceedings Annual Technical Conference Society of Vacuum Coaters, 2005
Hydrogen doping of ZnO:Al films deposited by pulsed DC-sputtering of ceramic targets Proceedings Annual Technical Conference Society of Vacuum Coaters, 2005
Model prediction and emprical confirmation of rate scaling with peak power for high power pulse magnetron sputtering (HPPMS) deposition of thin Ag films Proceedings Annual Technical Conference Society of Vacuum Coaters, 2005
Early Onset Degradation Mechanism in All Solid-State Batteries Revealed by Operando Photoelectron Spectroscopy KA Mazzio, E Kataev, F Piccolo, F Ruske, R Garcia-Diez, R Wilks, M Bär, ... ACS Energy Letters , 2026 2026
The effect of non-stoichiometry in Sb 2 Se 3 films on their phonon and electronic properties in the infrared range B Andriyevsky, L Bychto, A Patryn, T Razykov, B Ergashev, K Kouchkarov, ... Scientific Reports 15 (1), 33513 , 2025 2025
Ammonia tolerant alkaline oxygen reduction reaction on bimetallic cobalt spinels K Dharmaraj, R Hanna, F Ruske, D Douglas-Henry, I Lauermann, ... Chemical Engineering Journal, 167192 , 2025 2025 Citations: 2
Phenothiazine‐Based Self‐Assembled Monolayer with Thiophene Head Groups Minimizes Buried Interface Losses in Tin Perovskite Solar Cells V Stacchini, M Rastgoo, M Marčinskas, C Frasca, K Morita, L Frohloff, ... Advanced Energy Materials 15 (29), 2500841 , 2025 2025 Citations: 16
Tailored Crystallization Dynamics for Efficient and Stable DMSO‐Free Tin Perovskite Solar Cells S Zuo, A Tarasov, L Frohloff, K Prashanthan, F Ruske, M Lounasvuori, ... Advanced Science 12 (29), e01311 , 2025 2025 Citations: 7
In-situ temperature calibration for high temperature XRD experiments in vacuum demonstrated on pristine and Nb doped TiO2− x thin films D Freudenblum, G Gruber, R Schwiddessen, F Ruske, N Weinberger Journal of Alloys and Compounds 1036, 181844 , 2025 2025 Citations: 1
Texture‐Enhanced Mechanical Stability of Transparent Electrodes for Flexible Optoelectronics with Near‐Infrared Response S Rieckhoff, F Riesebeck, M Soldera, K Mayer‐Stillrich, Q Wang, F Ruske, ... Advanced Materials Interfaces 12 (11), 2400922 , 2025 2025 Citations: 3
Description of excitonic absorption using the Sommerfeld enhancement factor and band-fluctuations K Lizárraga, E Serquen, P Llontop, LA Enrique, M Piñeiro, E Perez, ... Journal of Physics D: Applied Physics 58 (6), 065102 , 2025 2025 Citations: 7
Texture-Enhanced Mechanical Stability of Transparent Electrodes for Flexible Optoelectronics with Near-Infrared S Rieckhoff, F Riesebeck, M Soldera, K Mayer-Stillrich, Q Wang, F Ruske, ... 2025
Seed layers for wide-band gap coevaporated perovskite solar cells: Cscl regulates band gap and reduces process variability V Skorjanc, A Miaskiewicz, M Ross, S Maniyarasu, S Severin, MR Leyden, ... ACS Energy Letters 9 (11), 5639-5646 , 2024 2024 Citations: 30
How to accelerate outdoor ageing of perovskite solar cells by indoor testing A Musiienko, NT Hartono, U Erdil, Z Nia, M Khenkin, H Köbler, ... 2024 Citations: 3
Enhanced electron extraction in co-doped TiO2 quantified by drift-diffusion simulation for stable CsPbI3 solar cells TW Gries, D Regaldo, H Koebler, TNH Putri, GV Sannino, EG Partida, ... arXiv preprint arXiv:2403.11982 , 2024 2024 Citations: 3
Transient grating spectroscopy on a DyCo5 thin film with femtosecond extreme ultraviolet pulses V Ukleev, L Leroy, R Mincigrucci, D De Angelis, D Fainozzi, NN Khatu, ... Structural Dynamics 11 (2) , 2024 2024 Citations: 4
Development of direct current magnetron sputtered TiO2− x thin films as buffer layers for copper indium gallium diselenide based solar cells D Stock, N Weinberger, F Ruske, L Haug, M Harnisch, R Lackner Thin Solid Films 786, 140115 , 2023 2023 Citations: 6
Minimizing Sputter Damage-Induced Electrical Losses in Monolithic Perovskite/Silicon Tandem Solar Cells During Deposition of the Transparent Front-Electrode M Härtel, B Li, S Mariotti, P Wagner, F Ruske, S Albrecht, B Szyszka 2023 IEEE 50th Photovoltaic Specialists Conference (PVSC), 1-1 , 2023 2023
Disentangling the effect of the hole-transporting layer, the bottom, and the top device on the fill factor in monolithic CIGSe-perovskite tandem solar cells by using … I Kafedjiska, G Farias Basulto, F Ruske, N Maticiuc, T Bertram, ... Journal of Physics: Energy 5 (2), 024014 , 2023 2023 Citations: 8
Reducing sputter damage-induced recombination losses during deposition of the transparent front-electrode for monolithic perovskite/silicon tandem solar cells M Härtel, B Li, S Mariotti, P Wagner, F Ruske, S Albrecht, B Szyszka Solar Energy Materials and Solar Cells 252, 112180 , 2023 2023 Citations: 38
Slot-die coated triple-halide perovskites for efficient and scalable perovskite/silicon tandem solar cells K Xu, A Al-Ashouri, ZW Peng, E Köhnen, H Hempel, F Akhundova, ... ACS energy letters 7 (10), 3600-3611 , 2022 2022 Citations: 109
Optimization of Silicon Heterojunction Interface Passivation on p‐and n‐Type Wafers Using Optical Emission Spectroscopy E Özkol, P Wagner, F Ruske, B Stannowski, L Korte physica status solidi (a) 219 (5), 2100511 , 2022 2022 Citations: 6
Optoelectrical analysis of TCO+ Silicon oxide double layers at the front and rear side of silicon heterojunction solar cells A Cruz, D Erfurt, P Wagner, AB Morales-Vilches, F Ruske, R Schlatmann, ... Solar Energy Materials and Solar Cells 236, 111493 , 2022 2022 Citations: 75
MOST CITED SCHOLAR PUBLICATIONS
Improved electrical transport in Al-doped zinc oxide by thermal treatment F Ruske, M Roczen, K Lee, M Wimmer, S Gall, J Hüpkes, D Hrunski, ... Journal of applied physics 107 (1) , 2010 2010 Citations: 263
Towards wafer quality crystalline silicon thin-film solar cells on glass J Haschke, D Amkreutz, L Korte, F Ruske, B Rech Solar Energy Materials and Solar Cells 128, 190-197 , 2014 2014 Citations: 145
Band lineup in amorphous/crystalline silicon heterojunctions and the impact of hydrogen microstructure and topological disorder TF Schulze, L Korte, F Ruske, B Rech Physical Review B—Condensed Matter and Materials Physics 83 (16), 165314 , 2011 2011 Citations: 145
High power pulsed magnetron sputtering of transparent conducting oxides V Sittinger, F Ruske, W Werner, C Jacobs, B Szyszka, DJ Christie Thin Solid Films 516 (17), 5847-5859 , 2008 2008 Citations: 143
Polycrystalline silicon thin-film solar cells on glass S Gall, C Becker, E Conrad, P Dogan, F Fenske, B Gorka, KY Lee, B Rau, ... Solar Energy Materials and Solar Cells 93 (6-7), 1004-1008 , 2009 2009 Citations: 129
ZnO: Al films deposited by in-line reactive AC magnetron sputtering for a-Si: H thin film solar cells V Sittinger, F Ruske, W Werner, B Szyszka, B Rech, J Hüpkes, G Schöpe, ... Thin Solid Films 496 (1), 16-25 , 2006 2006 Citations: 122
Slot-die coated triple-halide perovskites for efficient and scalable perovskite/silicon tandem solar cells K Xu, A Al-Ashouri, ZW Peng, E Köhnen, H Hempel, F Akhundova, ... ACS energy letters 7 (10), 3600-3611 , 2022 2022 Citations: 109
Optical characterization of aluminum-doped zinc oxide films by advanced dispersion theories A Pflug, V Sittinger, F Ruske, B Szyszka, G Dittmar Thin Solid Films 455, 201-206 , 2004 2004 Citations: 108
Optical modeling of free electron behavior in highly doped ZnO films F Ruske, A Pflug, V Sittinger, B Szyszka, D Greiner, B Rech Thin Solid Films 518 (4), 1289-1293 , 2009 2009 Citations: 107
Large area ZnO: Al films with tailored light scattering properties for photovoltaic applications F Ruske, C Jacobs, V Sittinger, B Szyszka, W Werner Thin Solid Films 515 (24), 8695-8698 , 2007 2007 Citations: 98
Optoelectrical analysis of TCO+ Silicon oxide double layers at the front and rear side of silicon heterojunction solar cells A Cruz, D Erfurt, P Wagner, AB Morales-Vilches, F Ruske, R Schlatmann, ... Solar Energy Materials and Solar Cells 236, 111493 , 2022 2022 Citations: 75
Microstructure and photovoltaic performance of polycrystalline silicon thin films on temperature-stable ZnO: Al layers C Becker, F Ruske, T Sontheimer, B Gorka, U Bloeck, S Gall, B Rech Journal of Applied Physics 106 (8) , 2009 2009 Citations: 72
Conversion efficiency and process stability improvement of electron beam crystallized thin film silicon solar cells on glass D Amkreutz, J Haschke, T Häring, F Ruske, B Rech Solar Energy Materials and Solar Cells 123, 13-16 , 2014 2014 Citations: 71
Improving the electrical and optical properties of DC-sputtered ZnO: Al by thermal post deposition treatments M Wimmer, F Ruske, S Scherf, B Rech Thin Solid Films 520 (12), 4203-4207 , 2012 2012 Citations: 62
Hydrogen doping of DC sputtered ZnO: Al films from novel target material F Ruske, V Sittinger, W Werner, B Szyszka, KU Van Osten, K Dietrich, ... Surface and Coatings Technology 200 (1-4), 236-240 , 2005 2005 Citations: 60
Influence of silicon layers on the growth of ITO and AZO in silicon heterojunction solar cells A Cruz, F Ruske, A Eljarrat, PP Michalowski, AB Morales-Vilches, ... IEEE Journal of Photovoltaics 10 (2), 703-709 , 2019 2019 Citations: 58
Influence of damp heat on the optical and electrical properties of Al-doped zinc oxide D Greiner, N Papathanasiou, A Pflug, F Ruske, R Klenk Thin Solid Films 517 (7), 2291-2294 , 2009 2009 Citations: 57
Temperature stability of ZnO: Al film properties for poly-Si thin-film devices KY Lee, C Becker, M Muske, F Ruske, S Gall, B Rech, M Berginski, ... Applied Physics Letters 91 (24), 241911-241911-3 , 2007 2007 Citations: 57
Damp heat stable doped zinc oxide films J Hüpkes, JI Owen, M Wimmer, F Ruske, D Greiner, R Klenk, U Zastrow, ... Thin Solid Films 555, 48-52 , 2014 2014 Citations: 56
Reactive deposition of aluminium-doped zinc oxide thin films using high power pulsed magnetron sputtering F Ruske, A Pflug, V Sittinger, W Werner, B Szyszka, DJ Christie Thin Solid Films 516 (14), 4472-4477 , 2008 2008 Citations: 55