Abstract

The “germanium-vacancy” (GeV) center in diamond can be used as Temperature Sensors. The idea of GeV-based thermometry is based on optical measurements of the spectral shift of the zero-phonon line and its spectral width as a function of temperature changes. At the same time optical characteristics of GeV center which is located near-surface could be modified by formation of defect states in the band gap based on surface impurities and dangling bonds. The electronic structure of the GeV center determines its optical properties. The goal of this study was to investigate comparatively the geometric characteristics and electronic structure of the GeV center in the volume and near-surface (100) of nanodiamond in cluster approximation. It was shown for the first time that formation of isolated dangling bond on the (100) diamond surface leads to formation of unoccupied state in the band gap in vicinity of 1 eV, which is located on the distance of 1.9 eV of conduction band edge. This state in the band gap may influence optical properties of GeV in diamond.

中文翻译：

---

用于温度传感器的GeV的电子和自旋特性的DFT模拟-体积和接近表面的纳米中心的色心

摘要

钻石中的“锗空位”（GeV）中心可用作温度传感器。基于GeV的测温方法的思想是基于零声子线的光谱位移及其随温度变化的光谱宽度的光学测量。同时，可以通过基于表面杂质和悬空键在带隙中形成缺陷状态来改变位于近表面的GeV中心的光学特性。GeV中心的电子结构决定了它的光学特性。这项研究的目的是在簇近似中比较研究GeV中心在纳米金刚石的体积和近表面（100）中的几何特征和电子结构。首次表明，在（100）金刚石表面上形成孤立的悬空键会导致在1 eV附近的带隙中形成未占据状态，该带隙位于导带边缘1.9 eV的距离上。带隙中的这种状态可能会影响金刚石中GeV的光学性质。