Thermographic, Electric, and Spectral Measurements for Analysis of High-Power LEDs

Effective temperature measurements are crucial for optimizing the design and performance of LEDs. This study presents a comprehensive investigation of LED temperature assessment using thermographic, electric, and spectral techniques. The complex thermal interactions within LEDs, such as the impact of phosphor layers and fill-in materials, pose challenges for accurate measurements. Thermography, while effective for LEDs with phosphor, faces limitations for phosphor-less LEDs due to low emissivities. To address this, an approach involving an optically-transparent infrared-opaque coating is proposed, demonstrated by tests on a thin film. This coating holds promise for improved thermographic measurements. In addition, spectral analysis of LED emission spectra reveals the potential to extract accurate temperatures for phosphor layers based on observed spectral shifts. Overall, this study advances LED temperature measurement methods, offering insights for enhanced accuracy and reliability in LED thermal analysis.