溴化银单晶/染料体系的光电行为

在(422)晶面的AgBr单晶表面上,真空升华所镀染料薄膜(厚约30nm)呈现均匀非晶聚集体。夹心器件:导电玻璃(受光面)/AgBr单晶/染料/Ag的光电流响应谱,与器件:Al/Al_2O_3(受光面)/染料/Ag很相近,可以认为AgBr的能带在与染料接触界面附近向上弯曲,类似于Al/Al_2O_3/染料界面的Schottky势垒,AgBr价带向上弯曲使空穴被“拉”向价带顶,导致部分自由电子复合以及减感。在AgBr单晶/染料体系中,对于增感染料,光电子从染料流向AgBr的导带;而对减感染料则相反。这些体系的伏安特性表明AgBr单晶中晶格与同隙离子之间的分布并不保持平衡。

Photoelectric behaviour for AgBr single crystal/dye systems

On the surface of AgBr single crystal (only (422)crystalface, d=0.118nm), vacuum-evaporated dye thin film (thickness about 30nm) exhibites uniform amorphous aggregation. The photocurrent of AgBr single crystal is very small. The action spectra of photocurrent between the "sandwich" configuration devices: conductive glass (incident light face)/AgBr single crystal/dye/Ag and Al/Al_2O_3/(incident light face)/dye/Ag are very similar. It can be concluded that the energy band of AgBr bend up nearby the interface of AgBr/dye as the Schottky barrier of the Al/Al_2O_3/dye interface. Because the valence band of AgBr also bend up, it is possible for the free holes to transfer to the top of valence band. This results in the recombination of the free electrons and desensitization. In AgBr single crystal/dye systems, the photoelectrons transfer from dye into AgBr phase for spectral sensitizers, and in reverse for spectral desensitive dyes. The voltampere curve (J-V) of AgBr single crystal/dye indicated that the distribution between lattice and interval ions in AgBr is not in equilibrium.