Piezo-phototronic effect on intersubband optical absorption in ZnO/MgZnO quantum wells

Intersubband transition in ZnO/MgZnO quantum well has been exploited for infrared and terahertz optoelectronic applications due to its large band offset and fascinating material properties. Here, we theoretically demonstrate piezo-phototronic effect as another way to control the intersubband absorption wavelength through quantum-confined Stark effect. The intersubband optical absorption properties under different stresses are obtained by solving the eight-band k⋅p Hamiltonian and coupled Schrödinger–Poisson equations self-consistently. By combining stress control and quantum well structure, the absorption wavelength can show infrared blueshift or redshift phenomena in a wide range. This work can provide an effective avenue to control and utilize quantum-confined Stark effect in intersubband infrared absorption and promote the relative potential optoelectronic devices.