Characters of native defects in p-type ZnO

Abstract

This paper reports on a new original method of radical beam quasi-epitaxy (RBQE), which enables us to obtain purest monocrystalline ZnO with p-type conductivity. We investigated electrical and optical properties of the p-type ZnO crystals obtained with the RBQE method. The photoluminescence (PL) spectrum of p-type basic sample of ZnO contains exciton area (367 – A-exciton, 369 – bound exciton, 374 nm – phonon replicas of A-exciton); 385 and 39 nm lines; and a non-structural line with maximum on 510 nm. In the PL spectra of new grown layers of ZnO was observed the peaks at 395 and 460 nm, while intensity of 510 nm lines was significantly reduced. Van der Pauw method was used for investigation of electrical properties of p-type ZnO layers. The basic p-type ZnO had holes concentration of 10^12 cm^–3, mobility 3.4 cm^2/V*s and resistivity 1.8*10^6 Ω*cm. The new p-type ZnO layers had parameters 10^15 cm^–3, 14 cm^2/V*s and 4.5*10^2 Ω*cm, respectively.