Tuning two-dimensional electron gas of ferroelectric/GaN heterostructures by ferroelectric polarization

Ferroelectric/semiconductor heterostructures are very attractive for future multifunctional and novel electronic devices. This paper examines the potential of devices based on heterostructures made from PbTiO3 (PTO) ferroelectric and GaN semiconductor. Our calculations combined the first principle and charge control model, which can derive basic material parameters (include effective mass and band offset) and two dimensional electric gas (2DEG) characters, respectively. Results showed that 2DEG density in GaN induced from PTO could reach 4.6 × 1013 cm−2, which is three times higher than that of from 20 nm Al0.3Ga0.7N. In the 8 nm PTO/20 nm Al0.3Ga0.7N/GaN structure, a positive polarization of 50 µC cm−2 could improve the 2DEG density to 1.9 × 1013 cm−2. Our theory predictions may provide some reference to the design of new electronic devices and promote experimental studies of ferroelectric/GaN heterostructures