A large and reversible upconversion (UC) luminescence modulation has been found in the Na_0.498Bi_0.498TiO₃:0.002Er (NBT:0.002Er) based on the photochromic reaction. The dependence of luminescence modulation of the ceramics on the wavelength of irradiation light and sintering temperature was investigated. It was found that the optimized sintering temperature and irradiation wavelength were 1130°C and 405 nm, respectively. The highest ΔR_t (defined as: ΔR_t = (R₀ – R_t)/R₀×100(%), where R₀ and R_t are the initial emission intensity and that after different irradiation time, respectively) value of 44.9% was obtained for the ceramics sintered at 1130°C after irradiation at 405 nm. More importantly, for the poled ceramics, ΔR_t value was promoted to a high value of 75.5%, which was 168% of that of the unpoled ones. The mechanism of luminescence modulation and its enhancement via electric field poling were discussed. This study demonstrated that electric field poling was an effective strategy to enhance the PC reaction in the NBT ceramics.

中文翻译：

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基于光致变色反应的掺Er3 +的Na0.5Bi0.5TiO3的上转换发光调制及其增强

基于光致变色反应，在Na _0.498 Bi _0.498 TiO ₃：0.002Er（NBT：0.002Er）中发现了较大且可逆的上转换（UC）发光调制。研究了陶瓷的发光调制对辐照光波长和烧结温度的依赖性。发现最佳的烧结温度和照射波长分别为1130℃和405nm。最高ΔR_吨（定义为：ΔR_吨=（R ₀ - R的_吨）/ R ₀ ×100（％），其中R ₀和R_吨分别是在405 nm照射后在1130°C烧结的陶瓷的初始发射强度和分别在不同的照射时间后的发射强度。该值分别为44.9％。更重要的是，对于极化陶瓷，ΔR_吨值被晋升为75.5％的高值，这是的是，未极化的那些的168％。讨论了发光调制的机理及其通过电场极化的增强作用。这项研究表明，电场极化是增强NBT陶瓷中PC反应的有效策略。