• 文献标题:   Exploring the effects of graphene and temperature in reducing electron beam damage: A TEM and electron diffraction-based quantitative study on Lead Phthalocyanine (PbPc) crystals
  • 文献类型:   Article
  • 作  者:   JAIN N, HAO YS, PAREKH U, KALTENEGGER M, PEDRAZOTARDAJOS A, LAZZARONI R, RESEL R, GEERTS YH, BALS S, VAN AERT S
  • 作者关键词:   electron diffraction, graphene, electron beam damage, lead phthalocyanine, cryogenic temperature, organic crystal
  • 出版物名称:   MICRON
  • ISSN:   0968-4328 EI 1878-4291
  • 通讯作者地址:  
  • 被引频次:   0
  • DOI:   10.1016/j.micron.2023.103444 EA MAR 2023
  • 出版年:   2023

▎ 摘  要

High-resolution transmission electron microscopy (TEM) of organic crystals, such as Lead Phthalocyanine (PbPc), is very challenging since these materials are prone to electron beam damage leading to the breakdown of the crystal structure during investigation. Quantification of the damage is imperative to enable high-resolution imaging of PbPc crystals with minimum structural changes. In this work, we performed a detailed electron diffraction study to quantitatively measure degradation of PbPc crystals upon electron beam irradiation. Our study is based on the quantification of the fading intensity of the spots in the electron diffraction patterns. At various incident dose rates (e/?,2/s) and acceleration voltages, we experimentally extracted the decay rate (1/s), which directly correlates with the rate of beam damage. In this manner, a value for the critical dose (e/?,2) could be determined, which can be used as a measure to quantify beam damage. Using the same methodology, we explored the influence of cryogenic temperatures, graphene TEM substrates, and graphene encapsulation in prolonging the lifetime of the PbPc crystal structure during TEM investigation. The knowledge obtained by diffraction experiments is then translated to real space high-resolution TEM imaging of PbPc.