Piezo-electric and -phototronic effects of perovskite 2D|3D heterostructures

Dimensionally-engineered perovskite heterostructures are highly attractive, as recently shown to be useful for enhancing the stability and efficiency in perovskite solar cells. Here, we first report piezo-electric and -phototronic effects found in two-dimensional (2D)|3D perovskite heterostructures under various pressures. The piezoelectric and -phototronic effects are strongly enhanced by employing 2D|3D heterostructure instead of a 3D single layer in the perovskite devices, which is believed to be due to energy-band modulation and bandmisalignment lessening by piezoelectrically-polarized charges induced under moderate compressive pressure. Furthermore, the perovskite 2D|3D piezo-electric and -phototronic device shows only a 29% reduction of its initial performance even under 30-days atmospheric conditions and almost perfect endurance properties. These results suggest that dimensionally-engineered perovskite heterostructures may provide a fundamentally good way to improve perovskite-based electronic and optoelectronic devices.