脉冲激光沉积法合成(Bi,Er)_2Ti_2O_7介电薄膜及其上转换发光

Synthesization of (Bi,Er)_2Ti_2O_7 Dielectric Thin Films by Pulse Laser Deposition Method and Its Up-Conversion Luminescence

采用脉冲激光沉积法在透明导电(ITO)玻璃衬底上制备(Bi,Er)_2Ti_2O_7介电薄膜。当沉积温度范围控制在500~600℃时,均可获得纯度较高的Bi_2Ti_2O_7薄膜。常温下,Bi_2Ti_2O_7薄膜的介电常数的范围为166~178,随频率和温度变化比较稳定,介电损耗低于0.05。通过分析光谱,发现薄膜的上转换光谱包含发光中心为527nm和548nm的绿光带及发光中心为660nm的红光带,分别对应Er^(3+)离子从发射能级~2 H_(11/2)、~4S_(3/2)和~4F_(9/2)向基态能级~4I_(15/2)的跃迁。(Bi,Er)_2Ti_2O_7薄膜是一种多功能材料,有望在透明光电器件中得到广泛应用。

（Bi, Er）2Ti2O7 dielectric thin films are synthesized on indium-tin-oxide （ITO） glass substrates by the pulse laser deposition method. The pure Bi2Ti2O7 thin films can be obtained when the deposition temperature is controlled in the range of 500~600 ℃. The range of dielectric constant of （Bi, Er）2 Ti2O7 thin film is 166~178 and the dielectric loss is less than 0.05 at room temperature. When the frequency and the temperature are changing, the dielectric constant remains stable. The spectral analysis shows that the up-conversion luminescence spectra of thin films contain two green light emission bands centered at 527 nm and 548 nm and a red light emission band centered at 660 nm. These emission bands correspond to the transition of Er3＋ from 2 Hll/2, 4Sa/2 and 4F9/2 levels to the ground level 4 I11/2 , （Bi, Er）2 Ti2 O7 thin films can be considered as a kind of multifunctional material, which will be widely applied to transparent optoelectronic devices in the future.