入射光强对Ag-BaO薄膜内场助光电发射特性的影响  

Influence of Light Intensity on Internal Field-Assisted Photoemission Characteristics of Ag-BaO Thin Film

作　　者：张琦锋[1] 吴锦雷[1] 

机构地区：[1]北京大学电子学系,北京100871

出　　处：《Journal of Semiconductors》2000年第12期1183-1188,共6页半导体学报（英文版）

基　　金：国家自然科学基金(批准号:69681001);北京市自然科学基金(批准号:2992019)

摘　　要：通过对不同光强入射下 Ag- Ba O薄膜内场助光电发射特性的测试 ,实验发现 Ag- Ba O薄膜内场助光电发射电流随内场助偏压的增长过程经历了快速增长和缓慢增加两个阶段 ,相应的转折电压大小与入射光强有关 .理论分析表明 ,内场助作用下 Ag- Ba O薄膜体内能带结构发生了 Ag微粒和 Ba O介质间等效界面势垒减小及薄膜表面真空能级相对下降等两个方面的变化 ,其在内场助作用过程中相对效果的不同导致了光电流增长过程中的两个阶段 ;Enhanced photoemission of Ag-BaO thin film under different light intensity was observed when an internal field-assisted bias was applied to the thin film. The increasing process of the photoemission current with the applied bias consists of fast stage and slow one, and between these two stages there is a transitional voltage related to the light intensity. The enhanced photoemission is explained as the decrease of interfacial barrier between Ag particles and BaO matrix and the degradation of vacuum level at the surface. The existence of transitional vo ltage is due to the different effects of the interfacial barrier and vacuum leve l on the photoemission enhancement. The influence of light intensity on the tran sitional voltage comes from the variations in the interior electric field, which are caused by the photogenerated-carriers in the thin films.

关 键 词：内场助光电发射 超微粒子-半导体薄膜 

分 类 号：TN304[电子电信—物理电子学]