Spontaneous self-formation of molecular ferroelectric heterostructures.

A new phase of diisopropylammonium perchlorate (DIPAP) forms during freeze-drying or heat treatment, which generates the heterostructure with its original ferroelectric phase. There is no composition fluctuation in the DIPAP molecular ferroelectric heterostructures, but there is an interface between the two phases of DIPAP. The formation of the new phase resembles that of martensite in alloys. A large internal bias field that is almost 2.5 times of the coercive field was found in the molecular ferroelectric heterostructures, which is comparable to that of doped triglycine sulfate. The large internal bias field will promote the ability of the DIPAP heterostructure to adsorb PM2.5 under light. The spontaneous self-formation of molecular ferroelectric heterostructures may help improve the performance of molecular ferroelectric devices.