Institute for Low Temperature Physics and Engineering NASU, 61103 Kharkov, Ukraine.
J Phys Chem A. 2011 Jun 30;115(25):7258-66. doi: 10.1021/jp2004419. Epub 2011 May 23.
The relaxation processes in pure and doped Ar films preirradiated by an electron beam are studied with the focus on charging effects. Correlated real time measurements have been performed applying current and optical activation spectroscopy methods. Thermally stimulated exoelectron emission and thermally stimulated luminescence are detected in the vacuum ultraviolet and visible range. An appreciable accumulation of electrons in the matrix is found, and prerequisites for negative space charge formation are ascertained. The part played by pre-existing and radiation-induced defects as well as dopants is considered and the temperature range of the electron trap stability is elucidated. It is shown that laser-induced electron detachment from O(-) centers results in an enhancement of electron detrapping via the chemiluminescence mechanism, viz. neutralized and thermally mobilized O atoms recombine. Formation of O(2)* results in the emission of visible photons. These photons act as a stimulating factor for electron release and transport, terminating in exoelectron emission and charge recombination. Chemiluminescence therefore plays an important role in the decay of charged centers.
用电子束预辐照的纯 Ar 及掺杂 Ar 薄膜的弛豫过程，研究重点为带电效应。采用电流和光致发光光谱学方法进行了相关的实时测量。在真空紫外和可见光范围内检测到热电子发射和热致发光。发现电子在基体中的大量积累，并确定了形成负空间电荷的前提条件。考虑了预存在和辐射诱导缺陷以及掺杂剂的作用，并阐明了电子陷阱稳定性的温度范围。结果表明，激光从 O(-)中心诱导电子脱离导致通过化学发光机制增强电子解吸，即中和和热激发的 O 原子重新结合。O(2)*的形成导致可见光光子的发射。这些光子作为电子释放和输运的刺激因素，最终导致热电子发射和电荷复合。因此，化学发光在带电中心的衰减中起着重要作用。
