Mehdizadeh-Rad Hooman, Sreedhar Ram Kiran, Mehdizadeh-Rad Farhad, Ompong David, Setsoafia Daniel Dodzi Yao, Elumalai Naveen Kumar, Zhu Furong, Singh Jai
Energy and Resources Institute and College of Engineering, IT and Environment, Charles Darwin University, Darwin, NT 0909, Australia.
Department of Electrical and Computer Engineering, University of Texas at Dallas, Dallas, TX 75080, USA.
Nanomaterials (Basel). 2022 Jan 27;12(3):420. doi: 10.3390/nano12030420.
Thermal stability, closely associated with the operating temperature, is one of the desired properties for practical applications of organic solar cells (OSCs). In this paper, an OSC of the structure of ITO/PEDOT:PSS/PHT:PCBM/ZnO/Ag was fabricated, and its current-voltage (-) characteristics and operating temperature were measured. The operating temperature of the same OSC was simulated using an analytical model, taking into consideration the heat transfer, charge carrier drift-diffusion and different thermal generation processes. The simulated results agreed well with the experimental ones. It was found that the thermalization of charge carriers above the band gap had the highest influence on the operating temperature of the OSCs. The energy off-set at the donor/acceptor interface in the bulk heterojunction (BHJ) was shown to have a negligible impact on the thermal stability of the OSCs. However, the energy off-sets at the electrode/charge-transporting layer and BHJ/charge-transporting layer interfaces had greater impacts on the operating temperature of OSCs at the short circuit current and maximum power point conditions. Our results revealed that a variation over the energy off-set range from 0.1 to 0.9 eV would induce an almost 10-time increase in the corresponding thermal power generation, e.g., from 0.001 to 0.01 W, in the cells operated at the short circuit current condition, contributing to about 16.7% of the total solar power absorbed in the OSC.
热稳定性与工作温度密切相关，是有机太阳能电池（OSC）实际应用所需的特性之一。本文制备了结构为ITO/PEDOT:PSS/PHT:PCBM/ZnO/Ag的有机太阳能电池，并测量了其电流-电压（-）特性和工作温度。使用考虑了热传递、电荷载流子漂移扩散和不同热产生过程的分析模型对同一有机太阳能电池的工作温度进行了模拟。模拟结果与实验结果吻合良好。研究发现，带隙以上电荷载流子的热化对有机太阳能电池的工作温度影响最大。结果表明，本体异质结（BHJ）中供体/受体界面处的能量偏移对有机太阳能电池的热稳定性影响可忽略不计。然而，电极/电荷传输层和BHJ/电荷传输层界面处的能量偏移在短路电流和最大功率点条件下对有机太阳能电池的工作温度影响更大。我们的结果表明，在短路电流条件下工作的电池中，能量偏移范围从0.1到0.9 eV的变化将导致相应热发电量几乎增加10倍，例如从0.001 W增加到0.01 W，约占有机太阳能电池吸收的总太阳能的16.7%。
