Regulating crystal growth of Cs2SnCl6 perovskite for rapid response and durable humidity-triggered non-contact sensor

Perovskite is proven to promote the surface dissociation of water molecules that are therefore applied in humidity-responsive electronics. However, inherent defects in crystals severely hinder structural stability and charge transfer which decline the performance of the devices. For this, we design a strategy to introduce Cs2SnCl6 perovskite into the graphene oxide reduction system, during which the growth and optimization of perovskite crystals are achieved, accompanied by the formation of interface coordination with semi-reduced graphene oxide, obtaining stability and durability humidity-sensitive non-contact sensors. The results prove that the sensor exhibits low latency in response (0.8 s) and recovery (1.9 s), excellent sensitivity (6.5 × 106), and long-term stability (over 240 days). Additionally, distinguishable signals can be output easily in multiple different non-contact sensing applications and gesture recognition applications can be successfully implemented, which provides a possibility of human–computer interaction.