中国物理B ›› 2020, Vol. 29 ›› Issue (9): 98801-098801.doi: 10.1088/1674-1056/aba5fc

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

Brahim Ait Ali, Reda Moubah, Abdelkader Boulezhar, Hassan Lassri   

  1. 1 LERDyS, Faculty of Science Ain Chock, Hassan II University of Casablanca, Morocco;
    2 LPMMAT, Faculty of Science Ain Chock, Hassan II University of Casablanca, Morocco
  • 收稿日期:2019-12-16 修回日期:2020-06-16 接受日期:2020-07-15 出版日期:2020-09-05 发布日期:2020-09-05
  • 通讯作者: Reda Moubah E-mail:reda.moubah@hotmail.fr

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

Brahim Ait Ali1,2, Reda Moubah2, Abdelkader Boulezhar1, Hassan Lassri2   

  1. 1 LERDyS, Faculty of Science Ain Chock, Hassan II University of Casablanca, Morocco;
    2 LPMMAT, Faculty of Science Ain Chock, Hassan II University of Casablanca, Morocco
  • Received:2019-12-16 Revised:2020-06-16 Accepted:2020-07-15 Online:2020-09-05 Published:2020-09-05
  • Contact: Reda Moubah E-mail:reda.moubah@hotmail.fr

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/Al 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.

关键词: organic materials, photovoltaics, Schottky barrier, barrier height

Abstract: 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/Al 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.

Key words: organic materials, photovoltaics, Schottky barrier, barrier height

中图分类号:  (Organic photovoltaics)

  • 88.40.jr
78.55.Kz (Solid organic materials) 73.30.+y (Surface double layers, Schottky barriers, and work functions) 33.15.Hp (Barrier heights (internal rotation, inversion, rotational isomerism, conformational dynamics))