Dr
Alex
Ramadan
School of Mathematical and Physical Sciences
Senior Lecturer
a.ramadan@sheffield.ac.uk
+44 114 222 4355
+44 114 222 4355
Hicks Building
Full contact details
Dr Alex Ramadan
Hicks Building
School of Mathematical and Physical Sciences
Hicks Building
Hounsfield Road
Sheffield
S3 7RH
- Profile
-
My research is focussed on new and emerging semiconductors and using them to develop technologies which can help to tackle climate change. I have a current focus on energy generation (through solar photovoltaics) and reducing energy consumption (more efficient light emitting diodes).
Much of my research is currently centred on metal halide perovskite semiconductors. Photovoltaics based on these materials are now rivalling silicon-based photovoltaics in terms of efficiency, a particularly impressive feat given this development has taken < 15 years, and now the challenge is ensuring their long-term stability so they can be used for real world deployment.
I am interested in understanding the surfaces and interfaces of optoelectronic devices based on metal halide perovskites and how this relates to their physical and electronic properties. Understanding this relationship will allow us to develop ways to improve the stability of metal halide perovskite devices and help them successfully enter the commercial market.This research is broad and interdisciplinary, covering the chemistry, physics, and materials science of these new and emerging semiconductors.
Alongside my research I am passionate about improving diversity and research culture in physics.
- Publications
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Journal articles
- The impact of C60-self-assembled monolayer electron-transport layers in negative–intrinsic–positive perovskite solar cells. ACS Energy Letters, 11(9), 6177-6186. View this article in WRRO
- Generative and multimodal AI for materials prediction and design: progress, challenges, and perspectives. Journal of Physics: Materials, 9(3). View this article in WRRO
- Crystal-growth-controlled exciton funneling in BA2MAPb2I7 Ruddlesden–Popper perovskite thin films. Molecules, 31(15). View this article in WRRO
- Mapping relaxation pathways and bottlenecks in 2D perovskite microcavities. Journal of Materials Chemistry C, 14(33), 15140-15151. View this article in WRRO
- Halide segregation governs interfacial charge-transfer pathways in mixed-halide perovskites. EES Solar, 2(3), 640-651. View this article in WRRO
- Optimizing perovskite solar cell interfaces with molecular bridges. National Science Review, 12(12). View this article in WRRO
- Alumina nanoparticles enable optimal spray-coated perovskite thin film growth on self-assembled monolayers for efficient and reproducible photovoltaics. Journal of Materials Chemistry C, 12(34), 13332-13342. View this article in WRRO
- Tailoring perovskite crystallization and interfacial passivation in efficient, fully textured perovskite silicon tandem solar cells. Joule, 8(10), 2811-2833. View this article in WRRO
- Celebrating and supporting early career researchers within underrepresented groups in materials science. Nature Communications, 15(1). View this article in WRRO
- Ultrasonic spray deposition of a passivating agent for spray‐coated, methylammonium‐free perovskite solar cells. Solar RRL, 8(2). View this article in WRRO
- Compositional transformation and impurity-mediated optical transitions in co-evaporated Cu2AgBiI6 thin films for photovoltaic applications. Advanced Energy Materials, 14(8). View this article in WRRO
- The role of the organic cation in developing efficient green perovskite LEDs based on quasi‐2D perovskite heterostructures. Advanced Functional Materials, 34(14). View this article in WRRO
- Ultrasonic spray deposition of a passivating agent for spray‐coated, methylammonium‐free perovskite solar cells. Solar RRL, 8(2). View this article in WRRO
- Methylammonium-free wide-bandgap metal halide perovskites for tandem photovoltaics. Nature Reviews Materials, 8(12), 822-838. View this article in WRRO
- Understanding the degradation of methylenediammonium and its role in phase-stabilizing formamidinium lead triiodide. Journal of the American Chemical Society, 145(18), 10275-10284. View this article in WRRO
- Open-circuit and short-circuit loss management in wide-gap perovskite p-i-n solar cells. Nature Communications, 14. View this article in WRRO
- Reducing nonradiative losses in perovskite LEDs through atomic layer deposition of Al2O3 on the hole-injection contact. ACS Nano, 17(4), 3289-3300. View this article in WRRO
- A universal perovskite nanocrystal ink for high‐performance optoelectronic devices. Advanced Materials, 35(8). View this article in WRRO
- Thermally stable perovskite solar cells by all-vacuum deposition. ACS Applied Materials and Interfaces, 15(1), 772-781. View this article in WRRO
- Solvent-free method for defect reduction and improved performance of p-i-n vapor-deposited perovskite solar cells. ACS Energy Letters, 7(6), 1903-1911. View this article in WRRO
- A theoretical framework for microscopic surface and interface dipoles, work functions, and valence band alignments in 2D and 3D halide perovskite heterostructures. ACS Energy Letters, 7(1), 349-357. View this article in WRRO
- Understanding and suppressing non-radiative losses in methylammonium-free wide-bandgap perovskite solar cells. Energy & Environmental Science, 15(2), 714-726. View this article in WRRO
- Thermally Stable Passivation toward High Efficiency Inverted Perovskite Solar Cells. ACS Energy Letters, 5(11), 3336-3343.
- A piperidinium salt stabilizes efficient metal-halide perovskite solar cells. Science, 369(6499), 96-102. View this article in WRRO
- Revealing Factors Influencing the Operational Stability of Perovskite Light-Emitting Diodes. ACS Nano, 14(7), 8855-8865.
- Understanding the Performance-Limiting Factors of Cs
2
AgBiBr
6
Double-Perovskite Solar Cells. ACS Energy Letters, 5(7), 2200-2207.
- CsPbBr3 Nanocrystal Films: Deviations from Bulk Vibrational and Optoelectronic Properties. Advanced Functional Materials, 30(19).
- Revealing the Stoichiometric Tolerance of Lead Trihalide Perovskite Thin Films. Chemistry of Materials, 32(1), 114-120.
- Oxidative Passivation of Metal Halide Perovskites. Joule, 3(11), 2716-2731.
- Enhancing the Charge Extraction and Stability of Perovskite Solar Cells Using Strontium Titanate (SrTiO3) Electron Transport Layer. ACS Applied Energy Materials, 2(11), 8090-8097.
- Overcoming Zinc Oxide Interface Instability with a Methylammonium‐Free Perovskite for High‐Performance Solar Cells. Advanced Functional Materials, 29(47).
- The Structure of VOPc on Cu(111): Does V═O
Point Up, or Down, or Both?. The Journal of Physical Chemistry C, 123(13), 8101-8111.
- Unravelling the Improved Electronic and Structural Properties of Methylammonium Lead Iodide Deposited from Acetonitrile. Chemistry of Materials, 30(21), 7737-7743.
- Impact of Bi3+ Heterovalent Doping in Organic–Inorganic Metal Halide Perovskite Crystals. Journal of the American Chemical Society, 140(2), 574-577.
- Unveiling the Influence of pH on the Crystallization of Hybrid Perovskites, Delivering Low Voltage Loss Photovoltaics. Joule, 1(2), 328-343.
- Processing Solvent-Dependent Electronic and Structural Properties of Cesium Lead Triiodide Thin Films. The Journal of Physical Chemistry Letters, 8(17), 4172-4176.
- Solution-Processed Cesium Hexabromopalladate(IV), Cs2PdBr6, for Optoelectronic Applications. Journal of the American Chemical Society, 139(17), 6030-6033.
- Selecting Phthalocyanine
Polymorphs Using Local Chemical Termination Variations
in Copper Iodide. The Journal of Physical Chemistry C, 120(8), 4448-4452.
- Growth of Large Crystalline Grains of Vanadyl‐Phthalocyanine without Epitaxy on Graphene. Advanced Functional Materials, 26(8), 1188-1196.
- Structural Templating in a Nonplanar Phthalocyanine Using Single Crystal Copper Iodide. Advanced Materials Interfaces, 2(7).
- From organic semiconductors to metal halide perovskites. Nature Reviews Clean Technology, 1(3), 180-180.
- Perovskite solar cells take the heat. Nature Energy, 8(11), 1186-1187.
- Horizons Community Board collection: solar energy conversion. Nanoscale Horizons, 6(11), 839-841.
- Metal composition influences optoelectronic quality in mixed-metal lead–tin triiodide perovskite solar absorbers. Energy & Environmental Science, 13(6), 1776-1787.
- Film formation of non-planar phthalocyanines on copper(
i ) iodide. RSC Advances, 6(97), 95227-95231.
- The effect of fluorination on the surface structure of truxenones. RSC Advances, 6(71), 67315-67318.
- Organic/inorganic epitaxy: commensurate epitaxial growth of truxenone on Cu (111). RSC Advances, 6(21), 17125-17128.
- The morphology and structure of vanadyl phthalocyanine thin films on lithium niobate single crystals. Journal of Materials Chemistry C, 4(2), 348-351.
- Ordered growth of vanadyl phthalocyanine (VOPc) on an iron phthalocyanine (FePc) monolayer. Physical Chemistry Chemical Physics, 17(44), 29747-29752.
- The influence of polar (0001) zinc oxide (ZnO) on the structure and morphology of vanadyl phthalocyanine (VOPc). RSC Advances, 5(81), 65949-65952.
- Exploring high temperature templating in non-planar phthalocyanine/copper iodide (111) bilayers. Journal of Materials Chemistry C, 3(2), 461-465.
- Selective nucleation of iron phthalocyanine crystals on micro-structured copper iodide. Phys. Chem. Chem. Phys., 16(46), 25404-25408.
Conference proceedings
- Truxenones on coinage metal surfaces: structure and epitaxial templating (Conference Presentation). Organic Field-Effect Transistors XVI (pp 22-22), 6 August 2017 - 10 August 2017.
- Novel surface passivation for wide-bandgap perovskites. Proceedings of the MATSUS Spring 2026 Conference, 23 March 2026 - 27 March 2026.
- Surface Potential Mapping at the Nanoscale: Using Kelvin Probe Force Microscopy to Examine the Impact of Molecular Passivation on Surface Photovoltage in Perovskite Semiconductors.. Proceedings of the MATSUS Spring 2026 Conference, 23 March 2026 - 27 March 2026.
- Understanding quasi-2D perovskite structures and their performance in LEDs. Proceedings of the Emerging Light Emitting Materials 2024, 16 October 2024 - 18 October 2024.
- Band engineering of nickel oxide interfaces and connection between absolute valence energy alignment and surface dipoles in halide perovskite heterostructures. Proceedings of the nanoGe Fall Meeting 2021, 18 October 2021 - 22 October 2021.
- Overcoming Zinc Oxide Interface Instability with Methylammonium-free Perovskites for High Performance Solar Cells. Proceedings of the 11th International Conference on Hybrid and Organic Photovoltaics, 12 May 2019 - 15 May 2019.
Datasets
- The role of the organic cation in developing efficient green perovskite LEDs based on 2D/3D perovskite heterostructures.
- Alumina nanoparticles enable optimal spray-coated perovskite thin film growth on self-assembled monolayers for efficient and reproducible photovoltaics.
- Ammonium thiocyanate enables in-situ structural templating of MAPbI3 via quasi-2D perovskite scaffold.
- Understanding surface potential dynamics of passivated perovskites via Kelvin Probe Force Microscopy.
- Crystal-Growth-Controlled Exciton Funneling in BA2MAPb2I7 Ruddlesden–Popper Perovskite Thin Films.
Preprints
- Benchmarking bandgap prediction in semiconductors under experimental and realistic evaluation settings, Springer Science and Business Media LLC.
- A Universal Perovskite Nanocrystal Ink for High-Performance Optoelectronic Devices, Elsevier BV.
- The impact of C60-self-assembled monolayer electron-transport layers in negative–intrinsic–positive perovskite solar cells. ACS Energy Letters, 11(9), 6177-6186. View this article in WRRO