Temperature-dependent barrier height inhomogeneities in PTB7:PC71BM-based organic solar cells

• 作者: Abdelkader Boulezhar Brahim Ait Ali Hassan Lassri Reda Moubah
• 来源期刊: 中国物理B（英文版）
• 年，卷（期）: 2020,（9）
• 所属期刊栏目: INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY
• 页码范围: 687-693
• 页数: 7页
• 语种: 英文
• DOI: 10.1088/1674-1056/aba5fc

摘要

We report on the temperature-dependent Schottky barrier in organic solar cells based on PTB7:PC71BM.The ideality factor is found to increase with temperature decreasing,which is explained by a model in which the solar cell is taken as Schottky barrier diode.Accordingly,the dark current in the device originates from the thermally emitted electrons across the Schottky barrier.The fittings obtained with the thermal emission theory are systematically studied at different temperatures.It is concluded that the blend/Ca/A1 interface presents great inhomogeneity,which can be described by 2 sets of Gaussian distributions with large zero bias standard deviations.With the decrease of temperature,electrons favor going across the Schottky barrier patches with lower barrier height and as a consequence the ideally factor significantly increases at low temperature.