Mechanism and Application of Optical Modulation of Terahertz Waves in a Perovskite Heterojunction

We investigated the mechanism and application of the modulation of terahertz waves using perovskite heterostructures. At the interface between PEDOT:PSS and the perovskite layers under excitation by an external light source, photogenerated carriers transferred from the perovskite layer to the PEDOT:PSS layer, which was accompanied by charge accumulation. A large number of photogenerated carriers scattered terahertz waves, thereby modulating the terahertz signal in the sample. The process of modulation and recovery of the terahertz signal by a perovskite material under external light is analogous to the principle of biological synapses, which are involved in memory and learning in animal brains. This enabled us to develop perovskite-based synaptic devices. The memory properties of perovskite heterojunction materials open up applications of terahertz technology.