Thin
film fabrication is necessary to realize the device integration
of organic–inorganic hybrid perovskites (OIHPs), and solution-based
crystallization methods have been employed widely to this end. Despite
the versatility of the solution approach, device fabrication using
typical “top-down” lithography is generally incompatible
with as-prepared OIHPs films because of the low stability of perovskites
to polar solvents involved in the lithographic process. Moreover,
solution-prepared perovskites usually exhibit irregular surface roughness,
implying the existence of randomly oriented crystal domains with a
large density of grain boundaries, which are ultimately detrimental
to the material properties. Here, we report a patterning of CH3NH3PbI3 (MAPbI3) thin films
using a photolithographically fabricated cross-linked copolymer template
on Si or SiO2 substrates via a chemical vapor deposition
(CVD) method. Perovskite patterning is accomplished by growing PbI2 precursor layers selectively on template patterns and subsequently
converting to MAPbI3 using CH3NH3I (MAI) in the vapor phase. We confirm that [0001]-oriented PbI2 nanoplatelets nucleate primarily on a Si or SiO2 surface and grow by surface diffusion from a polymer surface. The
MAPbI3 conversion process preserves the original pattern
morphology through the vapor–solid intercalation of MAI. Prototype
photodetector arrays based on MAPbI3 patterns are also
demonstrated. Our results highlight the advantages of the CVD patterning
of perovskite materials in large-scale production for a range of optoelectronic
applications.