Vacuum-filtration enabled large-area CsPbBr3 films on porous substrates for flexible photodetectors
All-inorganic perovskites (CsPbX3, X = Cl, Br, I) have been considered as the promising candidates for developing high-performance ﬂexible and lightweight optoelectronic devices due to the high absorption coefficient, mechanical durability, low-temperature synthesis ability and stable physiochemical property. However, limited by strong chemical bonds and really low solubility, the fabrication of pinhole-free large-scale inorganic perovskites films is still a great challenge, which impede its application in the flexible solar cell, photodetectors and light emitting diodes. Here, we report a vacuum-filtration method to deposit large-scale compact all-inorganic perovskite films from its nanosheets suspension on the arbitrary porous substrates, which allows control the uniformity and thickness of the perovskite films. The performance of fabricated flexible-photodetectors was highly improved by adding the proper amount of CNTs additives, which could maintain the low dark current density and increase the photo-responsivity by suppressing the photocarrier recombination. The improved photodetectors showed a large on/off ratio of > 1 x 104, a fast rise/decay time of 52/14 ms. Our flexible photodetectors demonstrated excellent mechanical bending capability with retained performance after bending 1000 cycles. Our deposition method could provide a universal route for inorganic materials for fundamental studies and practical applications.
- This article is part of the themed collection: Journal of Materials Chemistry C Emerging Investigators