1. Tunable emissive ▫$CsPbBr_3 /Cs_4PbBr_6$▫ quantum dots engineered by discrete phase transformation for enhanced photogating in field-effect phototransistorsHan Xiao, Siyuan Wan, Lin He, Junlong Zou, Andraž Mavrič, Yixi Wang, Marek Piotrowski, Anil Kumar Bandela, Paolo Samorì, Zhiming M. Wang, 2024, izvirni znanstveni članek Opis: Precise control of quantum structures in hybrid nanocrystals requires advancements in scientific methodologies. Here, on the design of tunable CsPbBr3/Cs4PbBr6 quantum dots are reported by developing a unique discrete phase transformation approach in Cs4PbBr6 nanocrystals. Unlike conventional hybrid systems that emit solely in the green region, this current strategy produces adjustable luminescence in the blue (450 nm), cyan (480 nm), and green (510 nm) regions with high photoluminescence quantum yields up to 45%, 60%, and 85%, respectively. Concentration‐dependent studies reveal that phase transformation mechanisms and the factors that drive CsBr removal occur at lower dilutions while the dissolution–recrystallization process dominates at higher dilutions. When the polymer‐CsPbBr3/Cs4PbBr6 integrated into a field‐effected transistor the resulting phototransistors featured enhanced photosensitivity exceeding 105, being the highest reported for an n‐type phototransistor, while maintaining good transistor performances as compared to devices consisting of polymer‐CsPbBr3 NCs.
Ključne besede: crystallization mechanisms, dilution-induced kinetic trapping, photogating effect, phototransistors, quantum dots
Objavljeno v RUNG: 26.06.2024; Ogledov: 964; Prenosov: 11
 Celotno besedilo (4,02 MB)
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2. CVD Growth of Molybdenum Diselenide Surface Structures with Tailored MorphologyM. Naeem Sial, Usman Muhammad, Binjie Zheng, Yanan Yu, Andraž Mavrič, Fangzhu Qing, Matjaž Valant, Zhiming M. Wang, 2018, izvirni znanstveni članek Opis: Controllable atmospheric pressure CVD has been optimized to grow transition metal dichalcogenide MoSe2 with tunable morphology at 750 °C on a silicon substrate with a native oxide layer of 250 nm. Utilizing tetrapotassium perylene-3,4,9,10-tetracarboxylate (PTAS) as a seed promoter and varying the vertical distance between the substrate and the precursor MoO3, different morphologies of MoSe2 were achieved, including 2D triangles, hexagons, 3D pyramids and vertically aligned MoSe2 sheets. We find that the shape of MoSe2 is highly dependent upon the distance h between the substrate and the precursor. The change in the morphology is attributed to the confinement of vapor (MoO3 and Se) precursors and their concentrations due to the change in h. These results are helpful in improving our understanding about the factors which influence the morphology (shape evolution) and also the continuous growth of MoSe2 films.
Ključne besede: Transition metal dichalcogenides, 2D materials, Seed promotor, Chemical vapor deposition, Molybdenum diselenide
Objavljeno v RUNG: 20.08.2018; Ogledov: 4745; Prenosov: 18
Celotno besedilo (2,68 MB) |
