Article presents the large scale synthesis of solution-processed 2D (CH₃(CH₂)₃NH₃)₂(CH₃NH₃)ₙ − 1PbₙI₃ₙ + 1 (n = 2, 3, and 4) perovskites, a family of layered compounds with composition-tunable bandgap, where inkjet printing was used to fabricate heterostructure, flexible photodetector devices. The flexible, inkjet-printed perovskite 2D heterostructures have significant potential for optoelectronic devices, which can enable broad possibilities with compositional tunability and versatility of the organohalide perovskites.