Correlation between electrical properties and growth dynamics for Si-doped Al-rich AlGaN grown by metal-organic chemical vapor deposition

Correlation between electrical properties and growth dynamics for Si-doped AlGaN with Al mole fraction above 60% has been investigated. It is found that the electron concentration decreases significantly when decreasing the growth rate, while the electron mobility experiences a non-monotonic process of increasing at first and then decreasing. Combination of secondary ion mass spectroscopy and panchromatic cathodoluminescence results, reveals that the evolution of electrical properties mainly originates from compensation of III vacancy (VIII) to Si dopant, making VIII-nSi complexes, i.e., the concentrations of VIII-nSi complexes increase with decreasing the growth rate, implying high growth rate principle is vital for n-AlGaN.