Surface modification of all-inorganic halide perovskite nanorods by a microscale hydrophobic zeolite for stable and sensitive laser humidity sensing.

Perovskite materials are very sensitive to environment which is beneficial for humidity sensing. However, the existing illuminating humidity sensor has low luminous efficiency and sensitivity. Besides, the stability of perovskite material remains a key issue to be resolved. Compared to luminescence, lasing is much more sensitive to the surrounding environmental situation. However, humidity sensing based on perovskite lasing has not been reported so far. In this work, all-inorganic halide perovskite CsPbBr3 nanorods with optical gain coefficient as high as 954 cm-1 were designed and fabricated. Moreover, microscale hydrophobic zeolite was introduced to modify perovskite for improved stability. It is interesting to note that the hydrophobic zeolite introduces strong scattering which is beneficial for a three-dimensional random lasing with a quality (Q) factor of 2263. Through the strategy of using lasing instead of luminescence, optical stability and sensitive laser humidity sensing was demonstrated, which exhibits high sensitivity and good reliability. This work provides a new idea of improved stability of perovskite, which will promote the practical application of perovskite materials and devices.