Enhanced Photoresponsivity of All-Inorganic (CsPbBr₃) Perovskite Nanosheets Photodetector with Carbon Nanodots (CDs)

• Main Authors: Hassan Algadi, Chandreswar Mahata, Janghoon Woo, Minkyu Lee, Minsu Kim, Taeyoon Lee
• Format: Article
• Language: English
• Published: MDPI AG 2019-06-01
• Series: Electronics
• Subjects: all-inorganic perovskite; CsPbBr₃; carbon nanodots; charge transfer; carrier separation; photodetectors
• Online Access: https://www.mdpi.com/2079-9292/8/6/678

A hybrid composite photodetector based on cesium lead bromine perovskite (CsPbBr₃) nanosheets and carbon nanodots (CDs) was fabricated on a quartz substrate by a one-step method of spin-coating and hot-plate annealing. The responsivity of the CsPbBr₃/CD hybrid composite photodetector was 608 mAW^−1 (under a 520-nm laser diode source applied at 0.2 mWcm^−2), almost three times higher than that of a CsPbBr₃-based photodetector (221 mAW^−1). The enhanced performance of the CsPbBr₃/CD photodetector is attributable to the high band alignment of the CDs and CsPbBr₃, which significantly improves the charge extraction at the CsPbBr₃/CD interface. Moreover, the hybrid CsPbBr₃/CD photodetector exhibited a fast response time with a rise and decay time of 1.55 and 1.77 ms, which was faster than that of a pure CsPbBr₃ based photodetector, indicating that the CDs accelerate the extraction of electrons and holes trapped in the CsPbBr₃ film.