Fine Tuning Ag(I)–Sb(III) Hybrid Iodides for Light Detection

Lead-free
hybrid double perovskite iodides (HDPIs) have piqued
increasing research interest due to their environmental friendliness
and high stability. However, such antimony-based HDPIs with strong
photocurrent response are currently very limited. Here, we successfully
design and construct five Ag(I)–Sb(III)-based HDPIs using two
types of cyclic aliphatic amines as A-site templates. Interestingly,
these Ag(I)–Sb(III) HDPIs exhibit relatively narrow band gaps,
preferred orientation, and high stability after being processed into
thin films on the indium tin oxide (ITO) substrate. Notably, under
illuminations of a xenon lamp, all HDPIs exhibit considerable photocurrent
responses, reaching a maximum difference of 17 μA·cm–2 for ASI 1, which is the highest among
lead-free halogen-based organic–inorganic hybrid compounds
to date. Combining the considerable photocurrents and the high stability,
the optoelectronic applications of two-dimensional Ag(I)–Sb(III)
HDPIs can be expected.