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 Cs 2 SnCl 6 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 × 10 6 ), 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.