Abstract

In conclusion, we report for the first time the deposition of a high quality diamond layer on a type la natural diamond anvil by MPCVD at a substrate temperature between 1800°-2100° C. The growth rate for this process is estimated to be between 50 and 400 um/hr. We believe that the presence of large concentrations of C₂ are critical to the observed rapid growth. Raman analysis confirms the crystallinity and phase purity of the deposit. Low temperature PL measurements show the enhanced incorporation of optical defect centers with ZPLs at 636, 575 nm due to the unintentional incorporation of nitrogen [1], and 737 nm due to silicon [6] (perhaps from the quartz microwave window). PL excitation studies of the 775 nm band, the origin of which is unknown [4], reveal that it is selectively pumped in the green (~ 500 nm) spectral region. Further investigation of this explosive diamond growth regime at high temperature is in progress, as is the development of further optical and direct methods to measure substrate temperature in-situ.