The on-surface synthesis method allows the fabrication of atomically precise narrow graphene nanoribbons(GNRs),which bears great potential in electronic applications.Here,we synthesize armchair graphene nanoribbons(AG...The on-surface synthesis method allows the fabrication of atomically precise narrow graphene nanoribbons(GNRs),which bears great potential in electronic applications.Here,we synthesize armchair graphene nanoribbons(AGNRs)and chevron-type graphene nanoribbons(CGNRs)array on a vicinal Au(111112)surface using 10,10′-dibromo-9,9′-bianthracene(DBBA)and 6,12-dibromochrysene(DBCh)as precursors,respectively.This process creates spatially wellaligned GNRs,as characterized by scanning tunneling microscopy.AGNRs show strong Raman linear polarizability for application in optical modulation devices.Different from the distinct polarization of AGNRs,only weak polarization exists in CGNRs polarized Raman spectrum,which suggests that the presence of the zigzag boundary in the nanoribbon attenuates the polarization rate as an important factor affecting the polarization.We analyze the Raman activation mode of CGNRs using the peak polarization to expand the application of the polarization Raman spectroscopy in nanoarray analysis.展开更多
界面能级调控是目前研究优化材料性能的关键步骤之一,界面问题也是目前研究热点。以Si/MoO_(3)界面为例,通过利用多功能光电子能谱仪在清洁后的硅片上蒸镀不同厚度的MoO_(3)并进行XPS及UPS表征,对其表面成分及界面能级进行分析,通过UPS...界面能级调控是目前研究优化材料性能的关键步骤之一,界面问题也是目前研究热点。以Si/MoO_(3)界面为例,通过利用多功能光电子能谱仪在清洁后的硅片上蒸镀不同厚度的MoO_(3)并进行XPS及UPS表征,对其表面成分及界面能级进行分析,通过UPS谱图得到功函数和价带顶,利用XPS谱图获取界面化学、界面相互作用等信息。原子力显微镜(atomic force microscope,AFM)表征结果证实,蒸镀膜的实际厚度和使用晶振表征的理论厚度相近。光电子能谱实验结果揭示:当薄膜的理论厚度低于50?时薄膜成分不完全是Mo^(6+),低于150?时仍能检测到Si信号;蒸镀的薄膜理论厚度达到100?(功函数为6.81 eV)后,功函数数值趋于稳定,这说明可以在厚度范围内通过控制蒸镀MoO_(3)的厚度调控Si/MoO_(3)的界面能级。在一定范围内,利用不同厚度的薄膜调控界面能级是提高材料性能的方法之一,表明光电子能谱是用于研究界面问题的有效且便捷的表征方法。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61901200)the Yunnan Fundamental Research Projects(Grant Nos.2019FD041,202101AU070043,202101AV070008+2 种基金202101AW070010)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.NXDB30010000)the Dongguan Innovation Research Team Program。
文摘The on-surface synthesis method allows the fabrication of atomically precise narrow graphene nanoribbons(GNRs),which bears great potential in electronic applications.Here,we synthesize armchair graphene nanoribbons(AGNRs)and chevron-type graphene nanoribbons(CGNRs)array on a vicinal Au(111112)surface using 10,10′-dibromo-9,9′-bianthracene(DBBA)and 6,12-dibromochrysene(DBCh)as precursors,respectively.This process creates spatially wellaligned GNRs,as characterized by scanning tunneling microscopy.AGNRs show strong Raman linear polarizability for application in optical modulation devices.Different from the distinct polarization of AGNRs,only weak polarization exists in CGNRs polarized Raman spectrum,which suggests that the presence of the zigzag boundary in the nanoribbon attenuates the polarization rate as an important factor affecting the polarization.We analyze the Raman activation mode of CGNRs using the peak polarization to expand the application of the polarization Raman spectroscopy in nanoarray analysis.
文摘界面能级调控是目前研究优化材料性能的关键步骤之一,界面问题也是目前研究热点。以Si/MoO_(3)界面为例,通过利用多功能光电子能谱仪在清洁后的硅片上蒸镀不同厚度的MoO_(3)并进行XPS及UPS表征,对其表面成分及界面能级进行分析,通过UPS谱图得到功函数和价带顶,利用XPS谱图获取界面化学、界面相互作用等信息。原子力显微镜(atomic force microscope,AFM)表征结果证实,蒸镀膜的实际厚度和使用晶振表征的理论厚度相近。光电子能谱实验结果揭示:当薄膜的理论厚度低于50?时薄膜成分不完全是Mo^(6+),低于150?时仍能检测到Si信号;蒸镀的薄膜理论厚度达到100?(功函数为6.81 eV)后,功函数数值趋于稳定,这说明可以在厚度范围内通过控制蒸镀MoO_(3)的厚度调控Si/MoO_(3)的界面能级。在一定范围内,利用不同厚度的薄膜调控界面能级是提高材料性能的方法之一,表明光电子能谱是用于研究界面问题的有效且便捷的表征方法。
