Białek Ewelina, Włodarski Maksymilian, Norek Małgorzata
Institute of Materials Science and Engineering, Faculty of Advanced Technologies and Chemistry, Military University of Technology, Str. gen Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland.
Institute of Optoelectronics, Military University of Technology, Str. gen. Sylwestra Kaliskiego 2, 00-908 Warsaw, Poland.
Materials (Basel). 2020 Jul 16;13(14):3185. doi: 10.3390/ma13143185.
In this work, the influence of a wide range anodizing temperature (5-30 °C) on the growth and optical properties of PAA-based distributed Bragg reflector (DBR) was studied. It was demonstrated that above 10 °C both structural and photonic properties of the DBRs strongly deteriorates: the photonic stop bands (PSBs) decay, broaden, and split, which is accompanied by the red shift of the PSBs. However, at 30 °C, new bands in transmission spectra appear including one strong and symmetric peak in the mid-infrared (MIR) spectral region. The PSB in the MIR region is further improved by a small modification of the pulse sequence which smoothen and sharpen the interfaces between consecutive low and high refractive index layers. This is a first report on PAA-based DBR with a good quality PSB in MIR. Moreover, it was shown that in designing good quality DBRs a steady current recovery after subsequent application of high potential (U) pulses is more important than large contrast between low and high potential pulses (U-U contrast). Smaller U-U contrast helps to better control the current evolution during pulse anodization. Furthermore, the lower PSB intensity owing to the smaller U-U contrast can be partially compensated by the higher anodizing temperature.
在这项工作中，研究了宽范围阳极氧化温度（5 - 30°C）对基于多孔阳极氧化铝（PAA）的分布式布拉格反射器（DBR）生长和光学性能的影响。结果表明，温度高于10°C时，DBR的结构和光子特性都会严重恶化：光子禁带（PSB）衰减、变宽并分裂，同时伴随着PSB的红移。然而，在30°C时，透射光谱中出现了新的谱带，包括中红外（MIR）光谱区域中的一个强而对称的峰。通过对脉冲序列进行微小修改，使连续的低折射率和高折射率层之间的界面变得平滑和清晰，MIR区域的PSB得到了进一步改善。这是关于基于PAA的DBR在MIR区域具有高质量PSB的首次报道。此外，研究表明，在设计高质量DBR时，施加高电位（U）脉冲后稳定的电流恢复比低电位和高电位脉冲之间的大对比度（U - U对比度）更重要。较小的U - U对比度有助于在脉冲阳极氧化过程中更好地控制电流变化。此外，由于较小的U - U对比度导致的较低PSB强度可以通过较高的阳极氧化温度得到部分补偿。
