Composition-Dependent Degradation of Hybrid and Inorganic Lead Perovskites in Ambient Conditions

In recent times, halide perovskites have attracted the attention of the scientific community because of their semiconducting properties, low cost, and easy synthesis methods; characteristics that make them suitable for application as solar cells and in other fields of electronics. However, these materials are subject to significant chemical and structural degradation and performance decrease over time. This degradation remains a critical factor that prevents their widespread use. In the present paper, we investigated the stability of different bromine-based perovskites: hybrid, MAPbBr3 (MA:NH3CH3+) and inorganic, CsPbBr3 and RbPbBr3. The samples were prepared via single-step solution synthesis as thin films on Au/Pd coated glass substrates and the ageing process was carried out in air within a climatic chamber maintained at 50 °C and 75%RH humidity. The structural and chemical evolution of the perovskites was evaluated as a function of the exposure time by means of AFM, and AR-XPS, while their optoelectronic properties were monitored by indirect bandgap measurement. We observed that the inorganic perovskites resulted more stable than mixed organic–inorganic perovskites. Nevertheless, degradation remains present and further studies are necessary if these materials are to be used for practical applications.