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Efficient FAPbI3-PbS quantum dot graphene-based phototransistors

Aynehband, S ; Sharif University of Technology | 2021

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  1. Type of Document: Article
  2. DOI: 10.1039/d1nj03139b
  3. Publisher: Royal Society of Chemistry , 2021
  4. Abstract:
  5. The high mobility of charge carriers in graphene (G) together with the ease of processing and tunable optical properties of colloidal quantum dots (CQD) has provided high-performance hybrids for the next generation of phototransistors. In order to get a higher quality film of PbS QDs, understanding the effect of the ligand exchange method is critical. So, to improve the interdot electronic coupling, we propose a new conducting ligand to prepare a dense and self-assembled active layer of FAPbI3-PbS quantum dots on G/Si/SiO2substrates. Quantum dot (QD) nanocrystalline films were preparedviatwo different procedures: liquid phase ligand exchange (LPE) and solid phase ligand exchange (SPE). SPE with formamidinium lead iodide significantly increases the packing density and surface coverage of the active layer on the graphene substrate. Efficient light absorption in the near IR region and reduced charge transport resistance in the QD film are demonstrated. The SPE fabricated graphene-based heterostructure phototransistors exhibit improved specific detectivity (by 34%) andION/IOFFratio (by 23%) as compared with LPE. Our findings pave a way to develop high-throughout graphene-based phototransistors based on FAPbI3-CQDs. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2021
  6. Keywords:
  7. Carrier mobility ; Graphene ; Iodine compounds ; IV-VI semiconductors ; Layered semiconductors ; Lead compounds ; Ligands ; Light absorption ; Nanocrystals ; Phototransistors ; Semiconductor quantum dots ; Sols ; Colloidal quantum dots ; Electronic coupling ; Graphene substrates ; Ligand exchange method ; Nano-crystalline films ; Specific detectivity ; Transport resistance ; Tunable optical properties ; Quantum efficiency
  8. Source: New Journal of Chemistry ; Volume 45, Issue 34 , 2021 , Pages 15285-15293 ; 11440546 (ISSN)
  9. URL: https://pubs.rsc.org/en/content/articlelanding/2021/nj/d1nj03139b