Carbon doped Aluminium Nitride (C-AlN) thin film was synthesized on Al and Cu substrates using RF sputtering and used as heat sink for high power LED. The optical properties of LED such as correlated color temperature (CCT) and brightness (LUX) was recorded by spectrometer and tested for various driving currents. Increased lux level was observed for high driving currents and showed the performance C-AlN thin film as good thermal interface material at high driving currents.The observed CCT values were in between 6180-6900 K and increased for high driving currents. At the lower driving current, CCT value was high for C-AlN on Cu than on Al.overall, the observed optical properties of LED using C-AlN thin film as thermal interface material was suggested to explore the usage of C doped AlN thin film as effective thin film thermal interface material for thermal management in solid state lighting applications.