瞬态光电流对有机薄膜光伏器件中肖特基接触的研究

制备了结构为氧化铟锡(ITO)/有机半导体/金属的有机薄膜光伏器件,电流--电压曲线显示其具有整流特性但有机半导体和电极间肖特基接触的内建电场方向很难判定.为了研究有机半导体和电极的肖特基接触特性,分别制备了结构为ITO/有机绝缘层/有机半导体/金属和ITO/有机半导体/有机绝缘层/金属的器件,通过调制激光照射下器件的瞬态光电流方向可容易判断有机半导体和电极间肖特基接触的内建电场方向,外加偏压下瞬态光电流的强度变化进一步证实了判断的正确性.

Investigation on Schottky contacts in organic thin film photovoltaic devices by transient photocurrent

The organic thin film photovoltaic device with a structure of tin indium oxide (ITO)/organic semiconductor/metal is fabricated. A rectifying behavior of the device is observed from the current-voltage characteristics. However, it is hard to judge the direction of internal electric field between the organic semiconductor and electrodes under Schottky contacts. In order to investigate the characteristics of Schottky contacts between the organic semiconductor and electrodes, the devices with the structures of ITO/organic insulator layer/organic semiconductor/metal and ITO/organic semiconductor/organic insulator layer/metal are fabricated. It is easy to judge the direction of internal electric field between the organic semiconductor and electrodes under Schottky contacts by the direction of transient photocurrent which is produced under the irradiation from the modulated laser. The correctness of judgement is further proved by the change of transient photocurrent intensity with a bias voltage applied.