n-Si(As):Yb1130nm四能级发光研究

在n-Si(As):Yb中首次观察到1130nm的尖锐发光.通过掺入Yb的剂量与发光强度的关系以及红外吸收、透射光谱的测量,讨论了敏化剂Yb与激活剂As之间能量传递过程.适当选取Yb与As的浓度比可提高发光效率.

STUDY OF 1130nm FOUR LEVEL LUMINESCENCE IN n-Si(As):Yb

The sharp luminescence of n-Si(As):Yb at 1130nm is reported for the first time in this paper. Its half width is 23.2nm. The three weak peaks with wavelength of 1190nm(1.04eV), 1150nm(1.08eV) and 1100nm (1.13eV), respectively, are also observed at the same time. However, the both peaks at 1190nm and 1100nm are observed only when the light signal is amplified. We think that the three lines are the phonon replicas.The experimental results demonstrate that the emission intensity at 1130nm increases with increasing Yb dose. For lower dopar.t ones, especially, the intensity is significantly increased with slightly increasing Yb dose. For the range of ion number between 5×1012 to 1×1013, the intensity is almostly proportional to Yb dose. The intersily increasing becomes gradual when Yb exceedes 1×1013 ions cm-2.In order to find the emission evidence, the absorption and tramsmi-ssion spectra (ATS) for the host and the luminescent samples were measured, respectively. Due to having no similar data previously, therefore, ATS oi n-Si(As):Er is shown for comparison to n-Se(As):Yb. Via an analysis we concluded that:the emission at 1130nm in n-Si(As):Yb does not arise from Si bandside; the excited energy of He-Ne laser (632.8nm) is not decrectly absorbed by As impurity in Si; and it does not arise from the radiative transition 2F5/2-2F7/2 of Yb3+ (4f13).Finally, we think that the emission is a result of both sensitizer Yb and activator As. Here Yb acts as a shallow acceptor and is in the vicinity of top of valent band in Si. The energy transfer procedure between Yb and As are discussed, and a four level luminescent mode is proposed. It is found that the luminescent efficiency can be improved by appropriate selection of concentration ratios between Yb and As.