Cr Interlayer Towards Effective Deposition of Diamond on Ti:Sapphire for Thermal Management Application

Abstract

The performance of solid-state lasers can be significantly improved by introducing diamonds for thermal management. However, synthesizing of high-performance diamond films remains difficult due to large mismatch. Here, we deposited diamond on a Ti:sapphire substrate by using a Cr interlayer for the first time. The seeded Cr layer was attributed to superior interfacial adhesion. 17% increasement of thermal conductivity was realized. The diamond film deposited on the Cr interlayers was under compressive stresses of 0.51 and 0.45 GPa according to Raman spectroscopy. The first-principles calculation proved the strong carbon adsorption capability of the Cr surface. Meanwhile, ~ 0.2% of oxygen was added to inhibit the non-diamond phase formation caused by catalysis of the Cr. This remarkable enhancement in performance offers a promising potential for the fabrication of high-power solid-state laser heat spreaders using diamond films.

Keywords: diamond, Thermal management, MPCVD, Chromium interface, Ti:sapphire