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Báo cáo hóa học: " Effect of the Nd content on the structural and photoluminescence properties of silicon-rich silicon dioxide thin film"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Effect of the Nd content on the structural and photoluminescence properties of silicon-rich silicon dioxide thin film | Debieu et al. Nanoscale Research Letters 2011 6 161 http www.nanoscalereslett.eom content 6 1 161 o Nanoscale Research Letters a SpringerOpen Journal NANO EXPRESS Open Access Effect of the Nd content on the structural and photoluminescence properties of silicon-rich silicon dioxide thin films Olivier Debieu Julien Cardin Xavier Portier Fabrice Gourbilleau Abstract In this article the microstructure and photoluminescence PL properties of Nd-doped silicon-rich silicon oxide SRSO are reported as a function of the annealing temperature and the Nd concentration. The thin films which were grown on Si substrates by reactive magnetron co-sputtering contain the same Si excess as determined by Rutherford backscattering spectrometry. Fourier transform infrared FTIR spectra show that a phase separation occurs during the annealing because of the condensation of the Si excess resulting in the formation of silicon nanoparticles Si-np as detected by high-resolution transmission electron microscopy and X-ray diffraction XRD measurements. Under non-resonant excitation at 488 nm our Nd-doped SRSO films simultaneously exhibited PL from Si-np and Nd3 demonstrating the efficient energy transfer between Si-np and Nd3 and the sensitizing effect of Si-np. Upon increasing the Nd concentration from 0.08 to 4.9 at. our samples revealed a progressive quenching of the Nd3 PL which can be correlated with the concomitant increase of disorder within the host matrix as shown by FTIR experiments. Moreover the presence of Nd-oxide nanocrystals in the highest Nd-doped sample was established by XRD. It is therefore suggested that the Nd clustering as well as disorder are responsible for the concentration quenching of the PL of Nd3 . Introduction Over the last decade there has been an increasing interest toward nanomaterials for novel applications. One of the challenging fields concerns silicon-compatible light sources which are getting more and more attractive since they can be integrated to .