Directly integrated mixed-dimensional van der Waals graphene/perovskite heterojunction for fast photodetection

Mixed-dimensional (2D/3D) van der Waals (vdW) heterostructures made with complementary materials hold a lot of promise in the field of optoelectronic devices. Beyond simple mechanical stacking, directly growing the single-crystal perovskite on 2D materials to construct a high-quality vdW heterojunction can better promote carrier transport. In this work, a monolithic integrated graphene/perovskite heterojunction device is fabricated by directly growing a single-crystal hybrid perovskite on monolayer graphene. Due to the strong interface coupling, the hybrid device achieves self-powering behavior and exhibits prominent photoresponse properties with a fast response speed of up to 2.05 μs. Moreover, the responsivity and detectivity can be boosted to up to 10.41 A W⁻¹ and 4.65 × 10¹² Jones under the actuation of −3 V bias. This technique not only improves the device performance, but also provides an effective guideline for the development of next-generation directly integrated vdW optoelectronic devices.