Thermal performance of LED fixed on CVD processed ZnO thin film on Al substrates at various O<sub>2</sub> gas flow rates

Abstract

Zinc oxide thin films were deposited on aluminium (Al) substrates by chemical vapor deposition (CVD) method and used as thermal interface materials in LED packages. Various driving current were used to test the thin film performance on LED and measure the parameter, such as thermal resistance and junction temperature. Field Emission Scanning Electron Microscopy analysis of ZnO thin film surface prepared at 5 sccm showed dense and uniform particles, and this is verified by Atomic Force Microscopy analysis. Energy dispersive X-ray Analysis of the thin films confirmed that the thin film are Zn rich. Low thermal resistance (33.92 K/W) and high value of difference in junction temperature (∆T j = 4.8 ℃) were noticed with ZnO thin film prepared at 5 sccm gas flow for 700 mA when compared with bare Al boundary conditions. Overall, ZnO thin film at 5 sccm flow can be effectively used as thermal interface material for high power LEDs.