STABLE ELECTROLUMINESCENCE AND ITS MECHANISM IN LASER CRYSTALLIZED A-SI-H A-SINX-H SUPERLATTICES/

We report visible and stable electroluminescence (EL) with an emission peak wavelength of 700 nm from laser-crystallized a-Si:H/a-SiNx:H sup erlattices (SLs) at room temperature. SL samples with an a-Si:H sublay er thickness of 4.0 nm were crystallized by Ar+ laser scanning through a solid phase crystallization process. X-ray diffraction (XRD) and Ra man scattering spectra demonstrate that nanocrystalline silicon (nc-Si ) was formed within these ultrathin a-Si:H sublayers. EL was obtained in a structure consisting of a semitransparent Au electrode/crystalliz ed SLs/300 nm n(+) a-Si:H/quartz substrate. When the current density i n the biased sample reached a threshold value of 5 mA/mm(2), a uniform and stable EL was emitted through the entire semitransparent Au elect rode. The light emission is attributed to radiative recombination rela ted to nc-Si contained in the crystallized SLs.