Photoluminescence Characterization of High-Purity Synthesized Diamond

Abstract
Photoluminescence (PL) properties of high-purity synthesized diamond are studied using the 5th-harmonic of a Nd:YAG laser. Free-exciton related emissions are dominant even at room temperature, which confirms high crystal perfection of the sample. The intensity of the FE-related peaks decreases at temperatures below 150 K, and existence of shallow trap centers is suggested. Also there exists a long-lived broad band in the visible region. These features cannot be observed by cathodoluminescence, and PL characterization is proved to be effective for characterization of such high-quality diamond.