Electrical and optical properties in rare earth-doped amorphous chalcogenides

硫系玻璃目前正在研究作为基质的稀土掺杂的光子器件，如光纤放大器或光纤激光器。硫系玻璃具有声子能量低、折射率高、近红外透明性好等优点，是一种极具发展潜力的新型材料，本文采用溅射法制备了稀土掺杂硫系玻璃（As_2Se_3）薄膜。研究了含和不含稀土（Pr）组分的薄膜的电学和光学性质。一般来说，硫系玻璃表现出各种光致效应，如缺陷产生和体积变化，因此这些基本性质进行了系统的研究。为了了解从硫族化合物到稀土离子的非辐射跃迁（能量传递机制未知），进行了噪声测量。这在世界上尚属首次。建立了测量系统，并将很快得到有用的结果。观察到稀土离子的光致发光。然而，目前信号非常微弱。这意味着样品仍然不合格。我的下一个目标是1）要制备好的样品，应该寻找溅射的最佳条件。2)对于无辐射跃迁，应发展噪声（1/f）理论。这些工程正沿着这一目标进行。

Chalcogenide glasses are currently being investigated as host media for rare earthdoped photonic devices such as fiber amplifiers or fiber lasers. Due to low phonon energies, high rfractive index, and higher transparency in the near infrared, chalcogenide glasses are very attractive and have a potential for such devices.In the present study, the thin films of rare earth- doped chalcogenides (As2Se3) were tried to prepare by a sputtering method. The electrical and optical properties have been studied for both with and without rare earth (Pr) component. In general, chalcogenide glasses show various photoinduced effects such as defect creation and volume changes and hence these basic properties were systematically studied. To know nonradiative transition from chalcogenide to rare earth ions (energy transfer mechanisms are unknown), a noise measurements were undertaken. This is the first time in the world. The measurement system was established and the useful results will be obtained soon. The photoluminescence from rare earth ions were observed. The signal is however very weak at present. This means the sample is still not qualified.My next target is 1) To prepare good samples, the best condition for sputtering should be looked for. 2) The theory for noise (1/f) should be developed for nonradiative transition. The works are going on along this purpose.