Title | Ag-BaO薄膜在电场作用下的可见——近红外波段光学吸收特性 |
Other Titles | Optical absorption of Ag-BaO thin film in the visible and near-infrared region with applied electric field |
Authors | 张琦锋 侯士敏 张耿民 刘惟敏 薛增泉 吴锦雷 |
Affiliation | 北京大学电子学系 北京100871 |
Keywords | 光吸收 金属超微粒子半导体复合薄膜 表面等离激元 杂质能级 optical absorption metallic ultrafine particles-semiconductor composite thin films surface plasmons impurity energy level |
Issue Date | 2001 |
Publisher | 物理学报 |
Citation | 物理学报.2001,(03),561-565. |
Abstract | 对超额Ba激活的Ag BaO复合薄膜在外加垂直表面电场作用下的光学吸收特性进行了测量 .结果显示 ,薄膜在可见—近红外光波段存在两个吸收峰 ,其中近红外光区的吸收峰强度随垂直表面电场的作用而降低 .理论分析表明 ,可见光区的主吸收峰源于埋藏在BaO半导体中的Ag超微粒子的表面等离激元共振吸收 ;近红外光区的次吸收峰则由BaO半导体基质中杂质能级的光吸收引起 ,杂质能级的产生与超额Ba在BaO晶体中造成的氧缺位有关 .在外加垂直表面电场作用下 ,BaO基质中的杂质发生电离 ,并导致杂质能级上束缚电子浓度减小 ,表现为薄膜在与杂质吸收相对应的光子能量范围内的光吸收随电场强度的增加而降低 The optical absorption properties of Ag-BaO composite thin film with excess barium were measured while a vertical electric field was applied on the film surface. Total two absorption peaks were observed in the visible and near-infrared region,and only the peak that lies in the near-infrared region was dependent on the applied electric filed,i.e.,the absorption intensity was decreased with the increasing electric field. The dominant peak in the visible region is attributed to the surface plasmons resonance of Ag ultrafine particles embedded into the BaO semiconductor matrix. However, the weaker one in the near-infraed region is considered to arise from the transition of bound electrons at impurity energy level of the BaO semiconductor matrix, and such an impurity energy level is related to the negative ion vacancies caused by the excess braium in the BaO crystal. When the external surface electric field was applied,some of the impurities in the BaO Semiconductor matrix were ionized,and which further resulted in a decrease of the density of bound electrons at the impurity energy level. So that,part of the optical absorption owing to the impurity energy level was decreased with the enhanced electric field. |
URI | http://hdl.handle.net/20.500.11897/22472 |
ISSN | 1000-3290 |
DOI | 10.3321/j.issn:1000-3290.2001.03.038 |
Indexed | SCI(E) EI 中文核心期刊要目总览(PKU) 中国科学引文数据库(CSCD) |
Appears in Collections: | 信息科学技术学院 |