Improving Performance of Hybrid Graphene–Perovskite Photodetector by a Scratch Channel

Abstract

As a remarkable potential material for optoelectronics, perovskite has been widely studied in photodetectors. Here, a channel structure on graphene is introduced to achieve efficient separation of carriers in perovskites by suppressing the leakage current. The fabricated horizontal graphene/perovskite/graphene (GPG) structure detector with a graphene–perovskite hybrid channel and a secondary perovskite channel shows a good performance with a responsivity of 22 mA W−1, on/off switch ratio of 2.6 × 103, and detectivity of 3.55 × 109 Jones at a bias voltage of 2 V and an effective area of 3 × 5 mm2. The channel prepared by a simple probe drawing process forms a horizontal Schottky structure that is effective in generating photocurrent. It is proposed that minimizing the thickness of the perovskite without reducing the absorption rate and maintaining one channel are effective ways to further improve the performance of the GPG detector. The photoresponse characteristics of the devices under illumination of different wavelengths are measured, showing wide spectral response range and linear optical power response. Finally, a flexible GPG detector on polyethylene terephthalate substrate is fabricated. It almost retains the same performance and shows good reliability and bendability.