Researchers from the University of Barcelona, Jaume I University, Slovak University of Technology and University of Valencia have realized graphene-enhanced hybrid photodetectors by integrating inkjet-printed mixed-phase CsPbBr₃/Cs₄PbBr₆ perovskite films directly onto graphene platforms. In this architecture, a high-mobility 2D graphene channel is intimately coupled to a photoconductive perovskite layer, enabling highly efficient photogating and broadband charge transport across the device.
The graphene channel serves as an ultrafast, low-noise pathway for photoinduced carriers, translating small changes in perovskite charge density into large modulations of graphene conductance. This strong photogating effect, together with the mixed-phase “raisin bread” perovskite morphology that confines and stores carriers, yields very high photoconductive gain. Furthermore, the use of chemical-vapor-deposition graphene and maskless inkjet printing allows direct perovskite deposition onto graphene without lithography on top of the 2D layer, preserving graphene quality and supporting integration on large-area and potentially flexible substrates.
As a result, the devices deliver impressive performance metrics, reaching responsivities above 5.7 × 10⁴ A W⁻¹ and detectivities exceeding 10¹⁶ Jones at 312 nm, placing them among the most sensitive graphene - perovskite hybrids reported to date. The broadband and high-gain response stems from the synergistic interaction between the perovskite’s strong light absorption and graphene’s exceptional carrier mobility, which together facilitate rapid carrier extraction and long-lived photogating. This combination is particularly attractive for weak-light sensing and imaging applications, where ultralow detectable power levels are critical.
Stability, often a bottleneck for perovskite-based devices, is also significantly improved through the composite perovskite microstructure and the protective Cs₄PbBr₆ matrix surrounding the photoactive CsPbBr₃ domains. The graphene channel, being chemically and thermally robust, further contributes to reliable operation under continuous bias and illumination.
Overall, this work highlights how coupling graphene with phase-engineered perovskites via scalable inkjet printing can push the limits of graphene optoelectronics, opening viable pathways for next-generation, high-performance broadband photodetectors in integrated and flexible photonic systems.
