title: Large degree of polarization of photoluminescence caused by anisotropic strain in nonpolar a-plane MgxZn1-xO layers grown by plasma-assisted molecular beam epitaxy.
abstract: A large degree of polarization (ρ) of photoluminescence (PL) approximate to 1 is obtained in each nonpolar a-plane MgxZn1-xO layer grown by plasma-assisted molecular beam epitaxy (MBE) with x=0.01, 0.03, and 0.10, respectively. Anisotropic in-plane strains are selectively introduced by using foreign substrates and doping with different Mg contents, which strongly modify the valence band structures, leading to anisotropic optical properties. A polarized Raman measurement shows that anisotropic in-plane strains along the y and z axes increase with the increasing Mg contents. Polarized PL spectra show that ρ gradually increases to 0.97 with decreasing in-plane strains, resulting from an increasing difference in transition energy (ΔE) between E⊥c and E‖c caused by a lift of the degeneracy of valence band structures. The obtained highly polarized emission is close to linear polarized light, which is desirable in the backlighting of liquid crystal displays.
authors.forename: X Y
authors.initials: XY
authors.lastname: Chen
authors.forename: X H
authors.initials: XH
authors.lastname: Pan
authors.forename: W
authors.initials: W
authors.lastname: Chen
authors.forename: S S
authors.initials: SS
authors.lastname: Chen
authors.forename: J Y
authors.initials: JY
authors.lastname: Huang
authors.forename: Z Z
authors.initials: ZZ
authors.lastname: Ye