Photodetector Based on All-inorganic Perovskite Quantum Dots with Ring Electrode

It is proposed that the vertical type photodetectors based on all-inorganic perovskite quantum dots (QDs) with the Au ring electrode in the structure of indium tin oxide (ITO)/ zinc oxide (ZnO)/ CsPbBr ₃ QDs/ Au. The incident light from the Au ring electrode side can be harvested directly by CsPbBr ₃ QD film and the photon-induced carriers are separated by the oblique electrode filed between the Au ring electrode and ITO electrode. As the high carrier mobility and long diffusion length of CsPbBr ₃ QDs, photodetectors have high on/off ratio and low operation voltage. The effect of ring electrode size on performance of photodetector is researched and the smallest active device area has the highest on/off ratio. The photodetectors with solution-processing method have feasibility on the flexible substrate.