Piezoelectric field-induced quantum-confined Stark effect in InGaN/GaN multiple quantum wells

In this paper, we present an experimental evidence for the piezoelectric fi eld-induced quantum-confined Stark effect (QCSE) on InGaN/GaN quantum wells . The optical transitions of In0.23Ga0.77N/GaN p-i-n MQWs were studied by u sing modulation spectroscopy (electrotransmission ET) at room temperature. Quantum-well-related signals are well resolved in our ET spectra. Clear ene rgy blue shifts in accordance with increasing reversed bias are observed in the ET spectra. The energy blue shift is attributed to the QCSE. The stren gth of piezoelectric field is found to be 1.9 MV/cm. We also show experimen tally how the piezoelectric field affects the energy shift in the strained MQWs.