Poly[nitrilo(diphenoxyphosphoranylidyne)] passivated MAPbI3 film achieves 21.36% efficiency and superior multivariate stability for air-processed perovskite solar cells

Because numerous adverse factors, such as unsuitable humidity and oxygen atmosphere, usually lead to imperfect perovskite crystallization and various surface defects, thus the perovskite films are susceptible to corrosion during their open-air environment preparation. Which severely reduce both the power conversion efficiency (PCE) and stability of ultimate device. Hence, in order to precisely alter the MAPbI 3 perovskite layer, a polymer passivation technique is used via adding Poly[nitrilo(diphenoxyphosphoranylidyne)] (PDPP) additive into green anti-solvent. PDPP not only possesses the flexibility of common polymer long chains, but also one of the few substances that can simultaneously form covalent bonds (Pb-O), halogen bonds (P-I) and hydrogen bonds (N…H) with perovskite lattices to inhibit the generation of vacancies. The high-quality perovskite thin films can profoundly enhance the photoelectricity performance of PSCs. PDPP also has certain electrical activity, hydrophobic properties and strong thermal stability, which beneficial for improving the stability of ultimate device. As a result, the air-processed PDPP-passivated optimal device (non-encapsulated) obtain 21.36% champion PCE and excellent multivariate stability (including humidity, temperature, sunlight exposure and bending). This straightforward, environmentally friendly and cost-effective approach can pave the way of its applicability.