Synthesis and Performance of BaAl2O4 with a Wide Spectral Range of Optical Absorption

✍ Scribed by L.-W. Zhang; L. Wang; Y.-F. Zhu

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 590 KB
• Volume: 17
• Category: Article
• ISSN: 1616-301X
• DOI: 10.1002/adfm.200700506

✦ Synopsis

Abstract

Oxygen‐deficient BaAl~2~O~4~, with strong optical absorption in the spectra range from 200 to 2500 nm, was prepared by a simple and economic thermal treatment of BaAl~2~O~4~ in a H~2~ gas flow. Further studies found that a molar ratio of oxygen vacancies of about 0.4 % existed in the prepared oxygen‐deficient BaAl~2~O~4~ sample. The influence of oxygen vacancies on the electronic band structures and optical absorption of BaAl~2~O~4~ are elucidated via first principle calculations. Oxygen vacancies introduce impurity states above the valence band; these impurities expand and enhance the optical absorption of BaAl~2~O~4~. This approach is proposed to develop a new type of optical materials and to be applicable to many wide bandgap materials.