ZnO is popular in applications as gas sensors, varistors and transparent conductors for thin film on LED optical properties.
A research study conducted for Chemical Vapor Deposition (CVD) used for the synthesis of ZnO thin film on Al substrates at various flow rates of O2 gas. ZnO thin film coated substrates were tested as thermal substrates on influencing the optical properties of high power LED at various operating currents. Spectrometer analysis showed that ZnO thin film prepared at 10 sccm O2 flow rate showed better performance by reducing the Color Correlated Temperature (CCT) at driving currents. CCT values were maintained with respect to driving currents by ZnO thin film interface at all driving currents than air interface (bare Al substrate). On luminous flux analysis, 5 sccm samples showed good performance on increasing the light of the give LED at all driving currents than bare Al boundary condition. The observed results were evidenced with help of particle size distribution analysis on all film surface using Nanoscope software. Overall, ZnO thin film deposited at low O2 flow rate would be an alternative to solid thin film interface material in electronic packaging applications.
The optical properties of LED were tested using ZnO thin film as thermal interface material synthesized by CVD method at various flow rate of O2 gas. ZnO thin film prepared at low O2 flow rate showed better performance on maintaining the CCT values of the LED and reduce the risk on color shifting. High level lux was noticed for the LED interfaced using ZnO thin film prepared at 5 sccm flow of O2 gas. The results were evidenced by observing optimum level particle size on the surface which make good thermal contact conductance with the LED package. It is concluded that the ZnO thin film prepared at low O2 flow rate by CVD process would be recommended for solid thin film thermal interface material application in solid state lighting applications. A detailed analysis on thin film material quality and their reliability is preferred for further development of ZnO thin film in thermal management.
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Aida bt Jamaludin, N., Shanmugan, S., & Mutharasu, D. (2017). Performance of Chemical Vapor Deposited ZnO thin film as thermal interface material on optical properties of LED. International Journal Of Research And Engineering, 4(4), 114-118.