MICROSTRUCTURES AND OPTICAL-PROPERTIES IN CRYSTALLIZED A-SI-H MULTIQUANTUM WELLS USING EXCIMER-LASER ANNEALING

The visible light emission from KrF excimer laser crystallized a-Si:H/ a-SiNx:H multi-quantum well (MQW) films at room temperature is reporte d. Both X-ray diffraction (XRD) and Raman scattering spectra provide e vidence for the crystallization of Si layers within the MQWs after las er annealing treatment. Transmission electron micrographs (TEM) show t he perfect conservation of the layered structures and proves the mecha nism of constrained crystallization by stable a-SiNx:H barrier layers during laser annealing. The peak wavelength of visible PL spectra of t he crystallized samples is around 640 nm (similar to 1.94 eV) and does not shift with different exposure energy. The FWHM of the PL peak bec omes narrower to 0.4 eV when the irradiation energy density is increas ed to 0.9 J/cm(2).