Piezo-phototronics in quantum well structures

Quantum well (QW) structures are formed in nanometer-thickness-scale semiconductors with different bandgaps in sandwiched configurations and can offer a wide variety of advantages as active layers for optoelectronic devices, e.g., laser diodes, light emit diodes, photodetectors, and solar cells. Due to the non-centrosymmetric crystal structure, the third-generation semiconductor, such as ZnO, AlN, GaN, and InN, can generate a piezopotential within the crystal by applying an external or internal strain and lead to an effective modulation of the optoelectronic device performance, which is also called piezo-phototronics. With reducing the feature size of materials into several tens of nanometers (e.g., forming QW structures), the multiway coupling effects of quantum physics and piezo-phototronics (coupling with piezoelectricity, photoexcitation, and semiconductor properties) make this research topic more attractive and open a new window for fabricating advanced intelligent optoelectronic devices. This Perspective reviews the recent advances of piezo-phototronics in QW structures, including the fundamental theories and device performance enhancements, and aims to offer a summary and outlook for future research directions and practical applications of piezo-phototronic QW devices.