Carrier density analysis in stressed n-doped GaN layers on sapphire

Description

Using micro-Raman spectroscopy on MOCVD slightly n-doped GaN on sapphire structures (1.5 x 10$^{15}$ cm$^{-3}$ – 6.5 x 10$^{15}$ cm$^{-3}$), we report a method to dissociate biaxial stress contribution from n carrier concentration contribution in A1(LO) Raman peak position. For all characterized samples, the main Raman peaks A$_1$(LO) and E$_2^H$ exhibit a linear dependency with a slope of ~1 due to biaxial stress and the intercept of the linear regression increases as n carrier density locally increases.

Abstract

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