Improved Thermal Stability of Polymer Solar Cells by Incorporating Porphyrins

Abstract

Thermal stability has been the important issue in organic solar cell, especially for the large scale fabrication and application in the future. In this work, a new strategy involving the introduction of porphyrin compound (BL) is proposed to prevent the [6,6]‐phenyl C61 butyric acid methyl ester (PC61BM) aggregation. The supramolecular interactions between PC61BM and BL are first demonstrated in PC61BM:BL binary blend, and then the effect of BL on P3HT:PC61BM blend is qualitatively and quantitatively studied by differential scanning calorimetry, UV–vis absorption spectroscopy, atomic force microscopy, optical microscopy, and fluorescence techniques. It is found that the BL addition not only stabilizes the morphology of P3HT:PC61BM blend films, but also shows a good ability to maintain the electron mobility by depressing the PC61BM crystallization. And the thermal stability of the devices based on P3HT:PC61BM:BL ternary blend films is therefore greatly improved. For example, 8 wt% BL doping drops the power conversion efficiency by 10.5% relative to its peak value after 48 h of annealing at 130 °C, while 71.5% of decrease is obtained for the device without BL after only 3 h of annealing. This strategy is preliminarily proved to be universal and will show great potentials in future commercialization of polymer solar cells.

Side‐Chain Engineering for Enhancing the Thermal Stability of Polymer Solar Cells

“…[ 3 ] Tremendous efforts have been made to obtain stable PSCs, [ 4 ] and the concept of morphological stability is particularly striking. [ 5 ] Although an optimal morphology with nanoscale phase separation and interpenetrating network is essential for achieving high device performance, [ 6 ] it turns out to be a metastable state, and readily moves toward to a thermodynamic equilibrium state to form large macrophase aggregations, which could be accelerated by the accumulated heat from sunlight irradiation in real application. [ 7 ] Therefore, developing feasible strategies for stabilizing the optimal morphology is highly desirable.…”

Thermally Stable Dibenzo[def,mno]chrysene‐Based Polymer Solar Cells: Effect of Thermal Annealing on the Morphology and Photovoltaic Performances

“…They exhibit almost identical active layer morphology without PCBM clusters upon thermal annealing at 100 and 180 °C. With these results, we confirmed that PTTC:PC 71 BM blends have morphological stability at high temperatures, which can account for the retention of device performances …”

Diethynylbenzo[1,2‐b:4,5‐b′]dithiophene‐based small molecule and cross‐conjugated copolymers for organic solar cells

“…By treating BDTTIPS with tetranbutylammoniumfluoride (TBAF, 1 M) in the dichloromethane solution at room temperature, the monomer BDTE was obtained in a good yield of 80%. It is worth noting that the monomer BDTE must be freshly prepared due to the photochemical instability of the alkyne . In addition, it should also be noted that compound BDTE exhibited poor solubility after removal of triisopropylsilyl.…”