Photochromic and energy storage properties in K 0.5 Na 0.5 NbO 3 -based ferroelectrics

The coupling of photochromic properties and ferroelectrics has captured increasing interest in field of photoelectric devices. However, it is still a challenge to achieve excellent photochromic properties and energy storage performances in a ferroelectric material at the same time. Here, a novel photoelectric multifunctional material of (K0.5Na0.5)NbO3:0.05Eu is obtained. Under visible light irradiation, the sample can effectively absorb and store visible light, showing a reversible photochromic reaction. Eu3+ doping well achieves the readout of visible light storage by tuning luminescence emission intensity, and the luminescent modulation ratio is up to 84%. Meanwhile, a recoverable energy storage density of 2.02 J cm−3, high energy storage efficiency of 75.4%, and fast discharge speed (80 ns) are simultaneously acquired because of Eu3+ doping-induced transition of normal ferroelectric to relaxor ferroelectric. The unique combination of photochromic properties and energy storage performances in ferroelectrics opens the door to the development of photoelectric multifunctional devices.