Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
National Center for Nanoscience and Technology, Beijing 100190, P.R. China.
Sci Rep. 2017 Jan 10;7:40134. doi: 10.1038/srep40134.
Organic solar cells (OSCs) have attracted great attention in the past 30 years, and the power conversion efficiency (PCE) now reaches around 10%, largely owning to the rapid material developments. Meanwhile with the progress in the device performance, more and more interests are turning to understanding the fundamental physics inside the OSCs. In the conventional bulk-heterojunction architecture, only recently it is realized that the blend/cathode Schottky junction serves as the fundamental diode for the photovoltaic function. However, few researches have focused on such junctions, and their physical properties are far from being well-understood. In this paper based on PThBDTP:PCBM blend, we fabricated OSCs with PCE exceeding 10%, and investigated temperature-dependent behaviors of the junction diodes by various characterization including current-voltage, capacitance-voltage and impedance measurements between 70 to 290 K. We found the Schottky barrier height exhibits large inhomogeneity, which can be described by two sets of Gaussian distributions.
有机太阳能电池（OSCs）在过去 30 年中引起了极大的关注，其能量转换效率（PCE）现已达到 10%左右，这在很大程度上归功于材料的飞速发展。与此同时，随着器件性能的进步，人们越来越关注对 OSCs 内部基本物理现象的理解。在传统的体异质结结构中，人们最近才意识到，共混/阴极肖特基结是光伏功能的基本二极管。然而，很少有研究关注此类结，它们的物理性质远未得到很好的理解。在本文中，我们以 PThBDTP:PCBM 共混物为基础，制备了能量转换效率超过 10%的 OSCs，并通过电流-电压、电容-电压和阻抗测量等各种特性研究，在 70 到 290 K 之间研究了结二极管的温度依赖性。我们发现肖特基势垒高度表现出很大的非均匀性，可以用两组高斯分布来描述。
