Improved Perovskite Solar Cells with an Environmentally Friendly Phthalocyanine Hole Extracting Interlayer

We investigate the use of phthalocyanine, from the family of multipurpose functional organic complexes, as an interlayer between the hole-selective contact and the perovskite in self-assembled monolayer-based p-i-n perovskite solar cells. This phthalocyanine interlayer effectively mitigated recombination losses that were occurring between the self-assembled hole-extraction monolayer based on the carbazole functional group and the perovskite film. Furthermore, the crystallinity of the perovskite semiconductor was enhanced, which reduced nonradiative recombination and resulted in an increase in shunt resistance and a higher open-circuit voltage. The efficiency improved from 18.4% to 20.2%. A similar boost in efficiency was found under indoor lighting conditions (from 27.3% to 30.1%). The tetra-3,5-dimethylphenoxy-zinc phthalocyanine (DMPO4) molecule synthesized for this work also enhanced device stability under ISOS-D1 tests with the average T80 increasing from 1134 h to 1347 h with its incorporation. A purpose-designed synthetic strategy, yielding a total E-factor below 200, broadens the practical applicability of these versatile and cost-effective molecular materials.