Akın Kara Duygu, Turgut Sevdiye Basak, Gultekin Burak
Solar Energy Institute, Ege University, 35000 Izmir, Turkey.
ACS Omega. 2025 Jul 23;10(30):33341-33352. doi: 10.1021/acsomega.5c03436. eCollection 2025 Aug 5.
In this study, we explore the effect of halogen-light-assisted (LA) annealing on the crystallization of poly-(3-hexylthiophene) (P3HT) films and the morphology of P3HT:[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) blends, along with their impact on organic solar cell performance. Samples were annealed at various temperatures (100-120 °C) and durations (5-15 min) using both conventional hot plate (HP) and LA methods. Structural analysis showed that LA annealing significantly enhanced the crystallinity of P3HT films through improved in-plane molecular stacking. For the P3HT:PCBM blend layers, the best film quality and device performance were achieved with LA annealing at 100 °C for 15 min, resulting in a power conversion efficiency (PCE) of 3.10% compared to 2.22% for the HP-annealed counterpart. We further evaluated blends with different P3HT:PCBM ratios (1:0.6, 1:1, and 1:1.4) and found that P3HT-rich compositions, especially 1:0.6, benefited most from LA annealing, achieving better film morphology and higher efficiency. Charge transport and recombination behavior were studied through time-resolved photoluminescence, light-intensity-dependent -, and space charge limited current measurements. These analyses confirmed that LA annealing improves charge carrier mobility, reduces trap densities, and minimizes nonradiative recombination. Overall, our results demonstrate that LA annealing is an effective and scalable method to enhance both the material quality and photovoltaic performance in P3HT:PCBM-based solar cells.
在本研究中，我们探究了卤素光辅助（LA）退火对聚（3 - 己基噻吩）（P3HT）薄膜结晶以及P3HT与[6,6]-苯基-C61-丁酸甲酯（PCBM）共混物形态的影响，以及它们对有机太阳能电池性能的影响。使用传统热板（HP）和LA方法在不同温度（100 - 120°C）和持续时间（5 - 15分钟）下对样品进行退火处理。结构分析表明，LA退火通过改善面内分子堆积显著提高了P3HT薄膜的结晶度。对于P3HT:PCBM共混层，在100°C下进行15分钟的LA退火可获得最佳的薄膜质量和器件性能，功率转换效率（PCE）为3.10%，而热板退火的对应样品为2.22%。我们进一步评估了不同P3HT:PCBM比例（1:0.6、1:1和1:1.4）的共混物，发现富含P3HT的组合物，尤其是1:0.6，从LA退火中受益最大，具有更好的薄膜形态和更高的效率。通过时间分辨光致发光、光强依赖性和空间电荷限制电流测量研究了电荷传输和复合行为。这些分析证实，LA退火提高了电荷载流子迁移率，降低了陷阱密度，并使非辐射复合最小化。总体而言，我们的结果表明，LA退火是一种有效且可扩展的方法，可提高基于P3HT:PCBM的太阳能电池的材料质量和光伏性能。
