Ag-BaO复合薄膜光吸收谱中的双峰结构

Double-peak Structure in Optical Absorption Spectrum of Ag-BaO Composite Thin Film

经超额Ba激活的Ag BaO复合薄膜光吸收谱显示 ,该薄膜样品在可见 近红外光波段存在 2个吸收峰。理论分析表明 ,位于可见光区的主吸收峰源于埋藏在BaO半导体中的Ag纳米粒子的表面等离子激元共振吸收 ;而位于近红外光区的次吸收峰则是由BaO半导体基质中杂质能级的光吸收引起的。杂质能级的产生与超额Ba在BaO晶体中造成的氧缺位有关。

The optical absorption properties of Ag-BaO composite thin film were measured, and two absorption peaks were observed in the visible and near-infrared bands. The dominant absorption peak in the visible region is considered to result from surface plasmon resonance of Ag nanoparticles embedded into the matrix. The other absorption peak is attributed to the transition of bound electrons at the impurity energy level of the BaO semiconductor matrix, and the presence of such an impurity energy level is related to the negative ion vacancies caused by the excess barium in the BaO crystal.