Effects of Structure of Alkylamino Groups on Photoelectronic Properties and Stability of Perovskite Materials

Taking organic precursors with different alkyl chain lengths and ammonium groups as raw materials, a series of perovskite materials with various alkylamino groups were synthesized by solution method. The effects of the structure of alkylamino groups on the photoelectronic properties and stability of the as-synthesized perovskites were investigated. The perovskite solar cells based on stable 1, 3-diaminopropane lead iodide (CH₂)₃(NH₃)₂PbI₄ light-absorption layer were fabricated in order to evaluate its application in the area of photovoltaics. The results show that the length of alkyl chain and the number of the ammonium groups directly affect the band gap of the perovskites, it increases with the increasing alkyl chain length, while decreases with the number of the ammonium groups. In particular, (CH₂)₃(NH₃)₂PbI₄ perovskite material synthesized from 1,3-dia-minopropane precursor exhibits an absorption cut-off edge at 930 nm and a high stability in the moist atmosphere. The photogenerated open-circuit voltage of the solar cell based on the (CH₂)₃(NH₃)₂PbI₄ absorber layers reaches 0.718 V. The photovoltaic materials with high photoelectric properties and high stability can be prepared by controlling the structure of anylamino groups.