Surface ionisation of molecular H 2 and atomic H Rydberg states at doped silicon surfaces
Surface ionisation of molecular H 2 and atomic H Rydberg states at doped silicon surfaces
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掺杂硅表面分子 H 2 和原子 H 里德伯态的表面电离
DOI：
10.1080/00268976.2014.940022
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发表时间：
2014
影响因子：
1.7
通讯作者：
Sashikesh G
中科院分区：
文献类型：
--
作者：
Sashikesh G
通过实验研究了掺杂 Si 表面入射的分子 H2 和原子 H 里德伯态的表面电离中的离子或电子的检测，以分析掺杂剂电荷分布对表面电离过程的影响。在这两项实验研究中，分子 H2 和原子 H 里德伯态都是通过双色真空紫外-紫外 (VUV-UV) 共振激发产生的。对于 H2，在存在电场的情况下会填充 N+= 2,n= 17 流形的各种斯塔克态。观察到的表面电离信号随表面掺杂剂浓度和类型的变化，显示出所有斯塔克态的相似特征。将这些离子检测的表面电离分布与通过电子检测获得的表面电离分布进行比较。对于这两种情况，观察到作为掺杂剂浓度和类型的函数的不同趋势，这可以通过与电子轨迹相比表面电荷对电离后离子轨迹的更大影响来解释。对于在没有斯塔克场的情况下填充主量子数的原子 H 里德伯态，观察到的行为类似于相同表面上分子 H2 里德伯态的相互作用，并且这些测量证实观察到的效应可归因于目标表面的性质，而不是特定的原子或分子里德伯物种。
The detection of ions or electrons from the surface ionisation of molecular H2and atomic H Rydberg states incident at doped Si surfaces is investigated experimentally to analyse the effect of the dopant charge distribution on the surface-ionisation processes. In both experimental studies, the molecular H2and atomic H Rydberg states are generated via two-colour vacuum ultraviolet--ultraviolet (VUV–UV) resonant excitation. For H2, various Stark states of theN+= 2,n= 17 manifold are populated in the presence of an electric field. The variation of the observed surface-ionisation signal with surface dopant concentration and type, shows similar characteristics for all the Stark states. A comparison is made between these ion-detected surface-ionisation profiles and those obtained via electron detection. Different trends as a function of dopant concentration and type are observed for the two cases, explained by the greater effect of surface charges on the post-ionisation ion trajectory compared to the electron trajectory. For the atomic-H Rydberg states with principal quantum numberpopulated in the absence of a Stark field, the observed behaviour is similar to the interaction of molecular H2Rydberg states at the same surfaces, and these measurements confirm that the observed effects are attributable to the nature of the target surface rather than the specific atomic or molecular Rydberg species.