Emission related to exciton‐polariton coupling in porous SiC

Abstract

The paper presents the results of SiC nanocrystal (NC) characterization using the photoluminescence (PL), its temperature dependence and X‐ray diffraction (XRD) techniques. It is revealed that original n‐type 6H‐SiC wafers and porous 6H‐SiC layers consisted inclusions of 2H‐SiC, 4H‐SiC, and 8H‐SiC polytypes. The photoluminescence study has shown that in porous SiC layers the emission intensity of high energy PL bands enlarges. Temperature dependences of high energy PL bands testify that these PL bands related to excitons bounded at nitrogen donors in different SiC polytypes. The PL intensity enhancement of donor‐bound exciton PL bands in the big size (50‐250nm) SiC nanocrystals has been attributed to the realization of exciton weak confinement and exciton‐polariton coupling in SiC nanocrystals. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)