FES Funded ProjectsOutputs
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Luminescence properties of rare-earth chalcohalides RE3Ge2-xSixS8I (RE = La, Ce, Pr) and Ce3Si2S8-ySeyI for potential application in phosphor-converted white LEDsT12-P01 University of Alberta | Activity | 2022-07-27 | Dundappa Mumbaraddi, Vidyanshu Mishra, Mohammad Jomaa, Xiaoyuan Liu, Abhoy Karmakar, "Sambhavi Thirupurasanthiran ", Al Meldrum, Andrew P Grosvenor, Vladimir K Michaelis, Mar, A. | One Dimensional Metal Oxide Semiconductors as Electron Transport Layers for High Efficiency Halide Perovskite Solar Cells (HPSCs)Organometal trihalide perovskite semiconductor solar cells (HPSCs) have ushered in a new paradigm in the field of photovoltaics due to their high performance, facile synthesis, low cost and excellent optoelectronic properties. For optimal performance, HPSCs require an electron transport layer (ETL) that ensures efficient contact with the perovskite active layer and selectively transfers photogenerated electrons to the underlying electrode while also blocking holes. We report HPSCs with photoconversion efficiencies as high as 17.6 % using TiO2 nanorods (NR) as the ETL and a mixed halide, mixed cation organometal perovskite FAxMA1-xPbBryI3-y with optimized composition as the active layer. We found that one-dimensional TiO2 NR ETLs not only improved electron transport but also introduced nanophotonic enhancements through a more optimal management of incident light. We used two distinct geometric configurations of nanorods, one in which the NRs were oriented vertically to the transparent conductive oxide (TCO) substrate, and another in which the NRs were roughly horizontally oriented with their longer axes in the substrate plane. Both types of NRs exhibited superior quenching of the perovskite photoluminescence compared to flat, planar ETLs indicating improved electron extraction. However, the horizontal NRs also exhibited a higher photonic strength in the form of a more directional light scattering. The enhanced forward scattering of light by the horizontal nanorods compared to the suppressed backscattering improved the utilization of incident light within the perovskite layer and increased light harvesting across a wide spectral range.T12-P02 University of Alberta | Activity | 2018-06-20 | Ujwal Thakur, Sheng Zeng, "Ashwin Lele ", Al Meldrum, Shankar, K. | Nanophotonic enhancement and improved electron extraction in perovskite solar cells using near-horizontally aligned TiO2 nanorodsWhile vertically oriented metal oxide nanowires have been intensely researched for use as electron transport layers (ETLs) in halide perovskite solar cells (HPSCs), horizontal nanowires (oriented roughly parallel to the substrate) have received much less attention despite their higher photonic strength due to overlapping electric and magnetic dipolar Mie resonance modes. Herein, we demonstrate the fabrication of an assembly of horizontally aligned TiO2 nanorods (HATNRs) on FTO substrates via a facile hydrothermal route. The HATNRs are employed as the ETL to achieve 15.03% power conversion efficiency (PCE) in HPSCs which is higher than the PCE of compact TiO2 based devices (10.12%) by a factor of nearly 1.5. A mixed halide, mixed cation organometal perovskite FA0.83MA0.17Pb(Br0.17I0.83)3 with optimized composition is used as the active layer. The excellent refractive index matching between the perovskite and TiO2, coupled with strong Mie scattering in the nanorod geometry results in broadband near-zero backscattering and high forward scattering, upon coating of HATNRs with perovskite. The maximum suppression of backscattering is found at ∼600 nm. The HATNRs ETL also improves the extraction of electrons from the perovskite layer and results in superior blocking of carrier recombination at the perovskite layer/FTO interface.T12-P02 University of Alberta | Publication | 2019-01-29 | Ujwal Thakur, Sheng Zeng, Pawan Kumar, Sahil Patel, Ryan Kisslinger, Yun Zhang, Piyush Kar, Ankur Goswami, "Thomas Thundat ", Al Meldrum, Shankar, K. | Ultrabright Fluorescent and Lasing Microspheres from a Conjugated PolymerT02-Z01 | Publication | 2018-06-21 | Kirsty Gardner, Maryam Aghajamali, "Vagin, S.", "Pille, J.", William Morrish, Jonathan G C Veinot, Al Meldrum, "Rieger, B." | A metal-organic framework with color-switching and strongly polarized emissionT02-Z01 | Publication | 2019-07-31 | Hui Wang, "Vagin, S.", "Lane, S.", "Lin, W.", "Shyta, V.", W R Heinz,, C Dyck, Van, A J Bergren,, Kirsty Gardner, "Rieger, B.", Al Meldrum | Ratiometric Detection of Nerve Agents by Coupling Complementary Properties of Silicon-Based Quantum Dots and Green Fluorescent ProteinT02-Z01 University of Alberta | Publication | 2019-08-15 | Christopher Robidillo, "Wandelt, S. ", "Dalangin, R. ", "Zhang, L. ", Haoyang Yu, Al Meldrum, "Campbell, R. ", Veinot, J. | Tailorable Indirect to Direct Band-Gap Double Perovskites with Bright White-Light Emission: Decoding Chemical Structure Using Solid-State NMR T12-Z01, T12-Q01 | Publication | 2020-05-01 | Abhoy Karmakar, Guy Bernard, Al Meldrum, Anton O Oliynyk, Vladimir K Michaelis | An Ultrasensitive Fluorescent Paper-Based CO2 SensorT02-Z01 | Publication | 2020-04-22 | Hui Wang, Al Meldrum, "Bernhard Rieger", "Sergei Vagin" | A Tale of Seemingly “Identical” Silicon Quantum Dot Families: Structural Insight into Silicon Quantum Dot PhotoluminescenceT06-Z01 University of Alberta | Publication | 2020-06-29 | Alyx Thiessen, Veinot, J., Lijuan Zhang, Anton O Oliynyk, Haoyang Yu, "Kevin O’Connor ", Al Meldrum | Blended Conjugated Polymer microspheres with "on demand" emission colorsT02-Z01 | Activity | 2021-01-27 | Tanisha Mehreen, Al Meldrum, "S. Wu", Hui Wang, "S. Vagin", "L. Zhang" | Blended Conjugated Polymer microspheres with "on demand" emission colorsT02-Z01 | Activity | 2020-11-10 | Tanisha Mehreen, "Zhang L", "Vagin S", Kirsty Gardner, "Wang H", "Wu S", Al Meldrum | Cerium-containing chalcohalides as tunable photoluminescent materialsT12-P01 University of Alberta | Activity | 2022-06-16 | Dundappa Mumbaraddi, Vidyanshu Mishra, Mohammad Jomaa, Abhoy Karmakar, Andrew P Grosvenor, Vladimir K Michaelis, Al Meldrum, Mar, A. |
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