Printed Lithography of Graphene-Perovskite Quantum Dot Hybrid Photodetectors on Paper Substrates

Paper is an ideal platform for creating flexible and eco-friendly electronic systems. Leveraging the synergistic integration of zero- and two-dimensional materials, it unfolds a broad spectrum of applications within the realm of the Internet of Things (IoT), spanning from wearable electronics to smart packaging solutions. However, for paper without a polymer coating, the rough and porous nature presents significant challenges as a substrate for electronics, and the absence of well-established fabrication methods further hinders its application in wearable electronics. In this study, we present photodetectors (PDs) on a paper substrate composed of graphene and CsPbBr₃ perovskite quantum dots (PQDs). Hybrid structures that combine PQDs with graphene offer a promising approach for PDs. These structures benefit from robust quantum confinement in PQDs alongside improved light interaction, tunable spectra, high absorption coefficients, and an enhanced photoconductive gain mechanism in graphene, all at ambient conditions. We use a microplotter for the lithographic printing of graphene, silver electrodes, and PQDs, to fabricate PDs on paper. These PDs have an external responsivity of ∼82,000 AW^-1 at 520 nm for an operating voltage ⩽1 V. The external responsivity is 3 orders of magnitude higher than state-of-the-art paper-based PDs. Under bending at L₀/L = 1.15 (L₀ is the arc length and L is the chord length) and after 600 bending cycles, the external responsivity is maintained up to 80%. Thus, the combination of zero- and two-dimensional materials via microplotting on a paper substrate shows promise for wearable and flexible applications.