Fig. 1: Schematic diagram of water environment temperature sensing.

Underwater temperature detection is achieved by exciting TPP3Cu2Br2 in water with 355 nm pump light to generate 524 nm green light. Benefiting from the excellent underwater stability and unique temperature-dependent luminescence lifetime of TPP3Cu2Br2, in the field of underwater temperature sensing, the lifetime-based TPP3Cu2Br2 material demonstrates extremely low error. This fully proves the reliability of lifetime-sensing technology in practical applications. Measured images reproduced from ref.32