--- DOAJ_listed: '1' OA_place: publisher OA_type: gold PlanS_conform: '1' _id: '21382' abstract: - lang: eng text: The exceptional energy-harvesting efficiency of lead-halide perovskites arises from unusually long photocarrier diffusion lengths and recombination lifetimes that persist even in defect-rich, solution-grown samples. Paradoxically, perovskites are also known for having very short exciton decay times. Here, we resolve this apparent contradiction by showing that key optoelectronic properties of perovskites can be explained by localized flexoelectric polarization confined to interfaces between domains of spontaneous strain. Using birefringence imaging, electrochemical staining, and zero-bias photocurrent measurements, we visualize the domain structure and directly probe the associated internal fields in nominally cubic single crystals of methylammonium lead bromide. We demonstrate that localized flexoelectric fields spatially separate electrons and holes to opposite sides of domain walls, exponentially suppressing recombination. Domain walls thus act as efficient mesoscopic transport channels for long-lived photocarriers, microscopically linking structural heterogeneity to charge transport and offering mechanistically informed design principles for perovskite solar-energy technologies. acknowledged_ssus: - _id: Bio - _id: M-Shop acknowledgement: We are grateful to A. G. Volosniev for the valuable discussions. We thank D. Milius for the assistance with microscopy. D. R. would like to thank F. Filakovský and T. Čuchráč for the valuable discussions. This research was supported by the Scientific Service Units (SSU) of ISTA through resources provided by the Imaging & Optics Facility (IOF) and the Miba Machine Shop Facility (MS). article_number: '946' article_processing_charge: Yes article_type: original author: - first_name: Dmytro full_name: Rak, Dmytro id: 70313b46-47c2-11ec-9e88-cd79101918fe last_name: Rak - first_name: Dusan full_name: Lorenc, Dusan id: 40D8A3E6-F248-11E8-B48F-1D18A9856A87 last_name: Lorenc - first_name: Daniel full_name: Balazs, Daniel id: 302BADF6-85FC-11EA-9E3B-B9493DDC885E last_name: Balazs orcid: 0000-0001-7597-043X - first_name: Ayan A. full_name: Zhumekenov, Ayan A. last_name: Zhumekenov - first_name: Osman M. full_name: Bakr, Osman M. last_name: Bakr - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 citation: ama: Rak D, Lorenc D, Balazs D, Zhumekenov AA, Bakr OM, Alpichshev Z. Flexoelectric domain walls enable charge separation and transport in cubic perovskites. Nature Communications. 2026;17. doi:10.1038/s41467-026-68660-5 apa: Rak, D., Lorenc, D., Balazs, D., Zhumekenov, A. A., Bakr, O. M., & Alpichshev, Z. (2026). Flexoelectric domain walls enable charge separation and transport in cubic perovskites. Nature Communications. Springer Nature. https://doi.org/10.1038/s41467-026-68660-5 chicago: Rak, Dmytro, Dusan Lorenc, Daniel Balazs, Ayan A. Zhumekenov, Osman M. Bakr, and Zhanybek Alpichshev. “Flexoelectric Domain Walls Enable Charge Separation and Transport in Cubic Perovskites.” Nature Communications. Springer Nature, 2026. https://doi.org/10.1038/s41467-026-68660-5. ieee: D. Rak, D. Lorenc, D. Balazs, A. A. Zhumekenov, O. M. Bakr, and Z. Alpichshev, “Flexoelectric domain walls enable charge separation and transport in cubic perovskites,” Nature Communications, vol. 17. Springer Nature, 2026. ista: Rak D, Lorenc D, Balazs D, Zhumekenov AA, Bakr OM, Alpichshev Z. 2026. Flexoelectric domain walls enable charge separation and transport in cubic perovskites. Nature Communications. 17, 946. mla: Rak, Dmytro, et al. “Flexoelectric Domain Walls Enable Charge Separation and Transport in Cubic Perovskites.” Nature Communications, vol. 17, 946, Springer Nature, 2026, doi:10.1038/s41467-026-68660-5. short: D. Rak, D. Lorenc, D. Balazs, A.A. Zhumekenov, O.M. Bakr, Z. Alpichshev, Nature Communications 17 (2026). corr_author: '1' date_created: 2026-03-02T10:06:58Z date_published: 2026-02-16T00:00:00Z date_updated: 2026-04-28T12:12:46Z day: '16' ddc: - '530' department: - _id: ZhAl - _id: LifeSc doi: 10.1038/s41467-026-68660-5 external_id: pmid: - '41698893' file: - access_level: open_access checksum: dd7a98de892d0b5abefca7e290ca0f77 content_type: application/pdf creator: dernst date_created: 2026-03-02T14:27:56Z date_updated: 2026-03-02T14:27:56Z file_id: '21390' file_name: 2026_NatureComm_Rak.pdf file_size: 2570918 relation: main_file success: 1 file_date_updated: 2026-03-02T14:27:56Z has_accepted_license: '1' intvolume: ' 17' language: - iso: eng month: '02' oa: 1 oa_version: Published Version pmid: 1 publication: Nature Communications publication_identifier: eissn: - 2041-1723 publication_status: published publisher: Springer Nature quality_controlled: '1' related_material: link: - description: News on ISTA website relation: press_release url: https://ista.ac.at/en/news/explaining-next-generation-solar-cells/ scopus_import: '1' status: public title: Flexoelectric domain walls enable charge separation and transport in cubic perovskites tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd volume: 17 year: '2026' ... --- OA_place: publisher OA_type: hybrid PlanS_conform: '1' _id: '20705' abstract: - lang: eng text: Optical tweezers are widely used as a highly sensitive tool to measure forces on micron-scale particles. One such application is the measurement of the electric charge of a particle, which can be done with high precision in liquids, air, or vacuum. We experimentally investigate how the trapping laser itself can electrically charge such a particle, in our case a ∼1  μ⁢m SiO2 sphere in air. We model the charging mechanism as a two-photon process which reproduces the experimental data with high fidelity. acknowledged_ssus: - _id: M-Shop - _id: ScienComp acknowledgement: We thank Todor Asenov and Abdulhamid Baghdadi for their outstanding technical support and Dr. Michael Gleichweit and Mercede Azizbaig Mohajer for the helpful discussions. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (Grant Agreements No. 949120 and No. 805041) and the Swiss National Science Foundation (SNSF, Project No. 200021-236446). This research was supported by the Scientific Service Units of the Institute of Science and Technology Austria (ISTA) through resources provided by the Miba Machine Shop and the Scientific Computing service unit. article_number: '218202' article_processing_charge: Yes (via OA deal) article_type: original arxiv: 1 author: - first_name: Andrea full_name: Stöllner, Andrea id: 4bdcf7f6-eb97-11eb-a6c2-9981bbdc3bed last_name: Stöllner orcid: 0000-0002-0464-8440 - first_name: Isaac C full_name: Lenton, Isaac C id: a550210f-223c-11ec-8182-e2d45e817efb last_name: Lenton orcid: 0000-0002-5010-6984 - first_name: Artem full_name: Volosniev, Artem id: 37D278BC-F248-11E8-B48F-1D18A9856A87 last_name: Volosniev orcid: 0000-0003-0393-5525 - first_name: James full_name: Millen, James last_name: Millen - first_name: Renjiro full_name: Shibuya, Renjiro last_name: Shibuya - first_name: Hisao full_name: Ishii, Hisao last_name: Ishii - first_name: Dmytro full_name: Rak, Dmytro id: 70313b46-47c2-11ec-9e88-cd79101918fe last_name: Rak - first_name: Zhanybek full_name: Alpichshev, Zhanybek id: 45E67A2A-F248-11E8-B48F-1D18A9856A87 last_name: Alpichshev orcid: 0000-0002-7183-5203 - first_name: Grégory full_name: David, Grégory last_name: David - first_name: Ruth full_name: Signorell, Ruth last_name: Signorell - first_name: Caroline J full_name: Muller, Caroline J id: f978ccb0-3f7f-11eb-b193-b0e2bd13182b last_name: Muller orcid: 0000-0001-5836-5350 - first_name: Scott R full_name: Waitukaitis, Scott R id: 3A1FFC16-F248-11E8-B48F-1D18A9856A87 last_name: Waitukaitis orcid: 0000-0002-2299-3176 citation: ama: Stöllner A, Lenton IC, Volosniev A, et al. Using optical tweezers to simultaneously trap, charge, and measure the charge of a microparticle in air. Physical Review Letters. 2025;135(21). doi:10.1103/5xd9-4tjj apa: Stöllner, A., Lenton, I. C., Volosniev, A., Millen, J., Shibuya, R., Ishii, H., … Waitukaitis, S. R. (2025). Using optical tweezers to simultaneously trap, charge, and measure the charge of a microparticle in air. Physical Review Letters. American Physical Society. https://doi.org/10.1103/5xd9-4tjj chicago: Stöllner, Andrea, Isaac C Lenton, Artem Volosniev, James Millen, Renjiro Shibuya, Hisao Ishii, Dmytro Rak, et al. “Using Optical Tweezers to Simultaneously Trap, Charge, and Measure the Charge of a Microparticle in Air.” Physical Review Letters. American Physical Society, 2025. https://doi.org/10.1103/5xd9-4tjj. ieee: A. Stöllner et al., “Using optical tweezers to simultaneously trap, charge, and measure the charge of a microparticle in air,” Physical Review Letters, vol. 135, no. 21. American Physical Society, 2025. ista: Stöllner A, Lenton IC, Volosniev A, Millen J, Shibuya R, Ishii H, Rak D, Alpichshev Z, David G, Signorell R, Muller CJ, Waitukaitis SR. 2025. Using optical tweezers to simultaneously trap, charge, and measure the charge of a microparticle in air. Physical Review Letters. 135(21), 218202. mla: Stöllner, Andrea, et al. “Using Optical Tweezers to Simultaneously Trap, Charge, and Measure the Charge of a Microparticle in Air.” Physical Review Letters, vol. 135, no. 21, 218202, American Physical Society, 2025, doi:10.1103/5xd9-4tjj. short: A. Stöllner, I.C. Lenton, A. Volosniev, J. Millen, R. Shibuya, H. Ishii, D. Rak, Z. Alpichshev, G. David, R. Signorell, C.J. Muller, S.R. Waitukaitis, Physical Review Letters 135 (2025). corr_author: '1' date_created: 2025-11-30T23:02:07Z date_published: 2025-11-21T00:00:00Z date_updated: 2026-04-28T13:09:27Z day: '21' ddc: - '530' - '550' department: - _id: ZhAl - _id: CaMu - _id: ScWa doi: 10.1103/5xd9-4tjj ec_funded: 1 external_id: arxiv: - '2507.17591' file: - access_level: open_access checksum: a5f76b1230cc7b039ecd0dbd6f99e775 content_type: application/pdf creator: dernst date_created: 2025-12-01T08:19:46Z date_updated: 2025-12-01T08:19:46Z file_id: '20717' file_name: 2025_PhysReviewLetters_Stoellner.pdf file_size: 1761373 relation: main_file success: 1 file_date_updated: 2025-12-01T08:19:46Z has_accepted_license: '1' intvolume: ' 135' issue: '21' language: - iso: eng month: '11' oa: 1 oa_version: Published Version project: - _id: 0aa60e99-070f-11eb-9043-a6de6bdc3afa call_identifier: H2020 grant_number: '949120' name: 'Tribocharge: a multi-scale approach to an enduring problem in physics' - _id: 629205d8-2b32-11ec-9570-e1356ff73576 call_identifier: H2020 grant_number: '805041' name: Organization of CLoUdS, and implications of Tropical cyclones and for the Energetics of the tropics, in current and waRming climate publication: Physical Review Letters publication_identifier: eissn: - 1079-7114 issn: - 0031-9007 publication_status: published publisher: American Physical Society quality_controlled: '1' related_material: link: - description: News on ISTA website relation: press_release url: https://ista.ac.at/en/news/trapping-particles-to-explain-lightning/ scopus_import: '1' status: public title: Using optical tweezers to simultaneously trap, charge, and measure the charge of a microparticle in air tmp: image: /images/cc_by.png legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0) short: CC BY (4.0) type: journal_article user_id: ba8df636-2132-11f1-aed0-ed93e2281fdd volume: 135 year: '2025' ...