Recycling Si Sludge from Semiconductor Manufacturing Processes into NIR-Reflective Black Materials for Autonomous Vehicles

초록

In this study, silicon sludge waste (Si-SW) generated from semiconductor manufacturing processes is converted into near-infrared (NIR)-reflective black materials. Initially, Si-SW is uniformly coated with white TiO2 via a sol-gel method (Si-SW/wTiO2). Subsequently, NaBH4 reduction changes the outer TiO2 layer from white to black (Si-SW/bTiO2), enhancing its optical properties. The resulting Si-SW/bTiO2 is dispersed in a hydrophilic varnish and painted onto a glass substrate, achieving an NIR reflectance of R% at 905 nm. This high NIR reflectance is attributed to the refractive index contrast between the Si-SW core and the black TiO2 shell, which follows Fresnel’s reflectance principle at the interfaces. A practical evaluation using rotating and MEMs mirror-type LiDAR sensors confirms the superior NIR reflectance of Si-SW/bTiO2. These results demonstrate that Si-SWs can be effectively utilized as NIR-reflective black materials, successfully recycling semiconductor waste into high-value advanced materials for next-generation applications. - Keywords: Semiconductor waste, Si sludge, Black TiO2, LiDAR sensor, Autonomous vehicle †Corresponding Author: cmyoon4321@inha.ac.kr