*Article* **Red Light Emitting Transition Metal Ion Doped Calcium Antimony Oxide for Plant Growth Lighting Applications**

**Lankamsetty Krishna Bharat 1,2, Harishkumarreddy Patnam 2, Alexander Sokolov 1, Sergey V. Gudkov 1,3,\* and Jae Su Yu 2,\***


**Abstract:** In this work, we synthesized Mn4+-doped CaSb2O6 phosphors using the conventional solid-state reaction method for plant growth lighting applications. The morphological, structural, and optical properties were analyzed based on the results obtained from scanning electron microscope, X-ray diffraction, and spectrophotometer. The results of the spectrophotometer illustrate that the phosphors showed a red emission band in 550–800 nm wavelength range with peak maxima at 642 nm. The red emission in these phosphors is attributed to the 2Eg <sup>→</sup> 4A2g transition of Mn4+ ions. The emission intensity is increased with the doping of a charge compensator. The emission range of the phosphor covers the absorption range of photosynthetic pigments such as chlorophyll a, chlorophyll b, phytochrome Pr, and phytochrome Pfr. The results signify that the prepared phosphor materials are suitable candidates for application in plant growth lighting.

**Keywords:** transition metal; charge compensator; red emission; artificial lighting; photosynthetic pigments
