Solution-possessed Vertical Photodetectors based on Composition Dependent Cesium Lead Halide (CsPbX3, X = Cl, Br, and I) Perovskite Quantum Dots

All-inorganic cesium lead halide perovskite quantum dots (PQDs) have been applied in optoelectronic fields owing to their unique properties including high carrier mobility, air stabilities and highly efficient photoluminescence. To overcome existing limitations in photodetection for light with particular wavelength and cost of state-of-the-art systems, new-style device structures and composite material systems are needed with low-cost fabrication and high performances. Here we synthesized the CsPbX3 (X = Cl, Br, and I) PQDs by changing the composition at room temperature and fabricated vertical field effect phototransistors (VFEpTs) with Au/Ag nanowires as the transparent source electrode and composition-dependent CsPbX3 (X = Cl, Br, and I) PQDs as active materials. It dominates to obtain photoresponse for specific wavelength in the visible spectrum and high performances. Particularly, VFEpTs based on CsPbCl1.5Br1.5 CsPbBr3, and CsPbBr1.5I1.5 PQDs are sensitive for blue, green, and red lights, respectively. It is worth mentioning that the device exhibits quantitative characterization for the contents of white light. Furthermore, CsPbX3 VFEpTs exhibit high performances including a short photoresponse time (less than 6 ms) and a high photoresponsivity (>9 x 10(4) AW(-1)). All-inorganic PQDs open up opportunities to integrate inorganic semiconductors, into high performances and flexible devices by using low cost, room temperature, large area, and solution based methods.