Fisher D, Sibley S J, Kelly C J
Diamond Trading Company, DTC Research Centre, Maidenhead, Berkshire SL6 6JW, UK.
J Phys Condens Matter. 2009 Sep 9;21(36):364213. doi: 10.1088/0953-8984/21/36/364213. Epub 2009 Aug 19.
Absorption spectroscopy results on a range of type II diamonds are presented which enable the electronic states associated with them to be mapped out. High pressure, high temperature treatment of brown type IIa diamonds has enabled an activation energy for the removal of the brown colour of 8.0 ± 0.3 eV to be determined and this is consistent with expectations associated with the currently accepted vacancy cluster model for the defect. Theoretical calculations suggest that this defect will generate partially filled gap states about 1 eV above the valence band. Data on the photochromic behaviour of bands producing pink colour and their relation to brown colour are presented; these suggest that the pink bands are produced from two independent transitions with ground states close to each other just below the middle of the band gap. Compensation of neutral boron by charge transfer from states associated with brown colour is demonstrated via the correlated increase in neutral boron and decrease in brown colour on high pressure, high temperature treatment to remove the defects causing the brown colour.
本文展示了一系列II型钻石的吸收光谱结果，这些结果能够描绘出与之相关的电子态。对棕色IIa型钻石进行高压高温处理后，已确定去除棕色的激活能为8.0±0.3电子伏特，这与当前公认的缺陷空位团簇模型的预期相符。理论计算表明，这种缺陷会在价带上方约1电子伏特处产生部分填充的能隙态。文中给出了产生粉红色的能带的光致变色行为数据及其与棕色的关系；这些数据表明，粉红色能带是由两个独立跃迁产生的，其基态彼此接近，刚好位于带隙中部下方。通过高压高温处理去除导致棕色的缺陷时，中性硼与棕色的相关增加和减少，证明了与棕色相关的态通过电荷转移对中性硼的补偿作用。
