Highly reproducible organometallic‐halide‐perovskite‐based devices are fabricated by a manufacturing process, which is demonstrated. Various shapes that are hard to synthesize directly are fabricated, and many unique properties are achieved.The fabrication procedure is utilized to create a photodetector and the detection sensitivity is significantly improved. The results will bring revolutionary advancement to the future of lead‐halide‐perovskite‐based optoelectronic devices.