Engineering of Porphyrin Molecules for Use as Effective Cathode Interfacial Modifiers in Organic Solar Cells of Enhanced Efficiency and Stability

Abstract

In the present work, we effectively modify the TiO electron transport layer of organic solar cells with an inverted architecture using appropriately engineered porphyrin molecules. The results show that the optimized porphyrin modifier bearing two carboxylic acids as the anchoring groups and a triazine electron-withdrawing spacer significantly reduces the work function of TiO, thereby reducing the electron extraction barrier. Moreover, the lower surface energy of the porphyrin-modified substrate results in better physical compatibility between the latter and the photoactive blend. Upon employing porphyrin-modified TiO electron transport layers in PTB7:PCBM-based organic solar cells we obtained an improved average power conversion efficiency up to 8.73%. Importantly, porphyrin modification significantly increased the lifetime of the devices, which retained 80% of their initial efficiency after 500 h of storage in the dark. Because of its simplicity and efficacy, this approach should give tantalizing glimpses and generate an impact into the potential of porphyrins to facilitate electron transfer in organic solar cells and related devices.

Progress in Stability of Organic Solar Cells

“…The origin of the bilayer strategy is similar to the doping and mixing strategy that an additional carrier transport layer can provide more stable interface contacts and act as the blocker for exterior and interior degradation factors in OSCs. [ 168,238–241 ]…”

Dye Sensitization of Titania Compact Layer for Efficient and Stable Perovskite Solar Cells

“…This can be attributed to the chemical bonding of the D35 dye to TiO 2 , strengthening their electronic coupling and inducing a faster electron injection rate. Such a mechanism was recently proposed by Tountas et al to explain the beneficial role of covalently bonded porphyrin molecules as effective cathode interfacial modifiers in inverted organic solar cells (OSCs). In addition, the midfrequency arc related to the recombination resistance ( R rec ) depicts a net increase in the case of the D35-modified device.…”

A Modified Triple-Diode Model Parameters Identification for Perovskite Solar Cells via Nature-Inspired Search Optimization Algorithms

“…The modified PSCs demonstrated significantly higher photovoltaic performance reaching power conversion efficiency (PCE) of 18.7%, clearly outperforming that of the control device (16.9%). This was attributed to better crystalized and more homogenous perovskite films [17,18], associated with a smoother and more functional ETL/absorber interface [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. The PCE enhancement for the modified devices was associated with the increase of Jsc and FF parameters, while the Voc value was…”