Mechanoluminescence enhancement of ZnS:Cu,Mn with piezotronic effect induced trap-depth reduction originated from PVDF ferroelectric film

Highlights: • A novel design of multilayered ML device was proposed by integrating the ZnS:Cu, Mn phosphors and PVDF thin film. • The mechanism of the enhancement of ML property based on the external piezoelectric fields was discussed. • This self-powered design with the enhanced ML response would benefit the ML device in a practical application. -- Abstract: Mechanoluminescence is a light emission process that is induced by a mechanical stimulus. The mechanisms that have been proposed to mediate this effect include elastic potential energy conversion and piezoelectric field-induced release of trapped charges for recombination. However, how to enhance this phenomenon is an open question for the application of mechanoluminescent (ML) effect. Herein, an effective ML enhancement approach was suggested through piezotronic effect driven trap-depth reduction of typical ML material (ZnS:Cu,Mn) based on charge release of ferroelectric polyvinylidene fluoride (PVDF) film. The experimental results illustrated that a layer of PVDF film covered on the both sides of ZnS:Cu,Mn ML layer can be nearly double the ML intensity in the particular external pressure, compared to that of the individual ZnS:Cu,Mn films. The films with an enhanced ML property show high potential for use in real-time pressure mapping systems, smart sensor networks, high-level security systems, and artificial intelligence.