title: Improved p-type conductivity in Al-rich AlGaN using multidimensional Mg-doped superlattices.
abstract: A novel multidimensional Mg-doped superlattice (SL) is proposed to enhance vertical hole conductivity in conventional Mg-doped AlGaN SL which generally suffers from large potential barrier for holes. Electronic structure calculations within the first-principle theoretical framework indicate that the densities of states (DOS) of the valence band nearby the Fermi level are more delocalized along the c-axis than that in conventional SL, and the potential barrier significantly decreases. Hole concentration is greatly enhanced in the barrier of multidimensional SL. Detailed comparisons of partial charges and decomposed DOS reveal that the improvement of vertical conductance may be ascribed to the stronger pz hybridization between Mg and N. Based on the theoretical analysis, highly conductive p-type multidimensional Al0.63Ga0.37N/Al0.51Ga0.49N SLs are grown with identified steps via metalorganic vapor-phase epitaxy. The hole concentration reaches up to 3.5 × 10(18) cm(-3), while the corresponding resistivity reduces to 0.7 Ω cm at room temperature, which is tens times improvement in conductivity compared with that of conventional SLs. High hole concentration can be maintained even at 100 K. High p-type conductivity in Al-rich structural material is an important step for the future design of superior AlGaN-based deep ultraviolet devices.
authors.affiliation: Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen, 361005, China.
authors.forename: T C
authors.initials: TC
authors.lastname: Zheng
authors.affiliation: Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen, 361005, China.
authors.forename: W
authors.initials: W
authors.lastname: Lin
authors.affiliation: SIMS Lab, Office of the Deputy Vice Chancellor and Vice President, Research and Development, Western Sydney University, Locked Bag 1797 Penrith NSW 2751.
authors.forename: R
authors.initials: R
authors.lastname: Liu
authors.affiliation: Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen, 361005, China.
authors.forename: D J
authors.initials: DJ
authors.lastname: Cai
authors.affiliation: Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen, 361005, China.
authors.forename: J C
authors.initials: JC
authors.lastname: Li
authors.affiliation: Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen, 361005, China.
authors.forename: S P
authors.initials: SP
authors.lastname: Li
authors.affiliation: Department of Physics, OSED, Fujian Provincial Key Laboratory of Semiconductor Materials and Applications, Xiamen University, Xiamen, 361005, China.
authors.forename: J Y
authors.initials: JY
authors.lastname: Kang