Sacrificial Layer for Sintering Enhancements of Ceramic, Semiconductor, and Metal Films: A Universal Strategy

The manufacturing of thin films through selective laser sintering of micro/nanoparticles is an emerging technology that has been developing rapidly over the last two decades owing to its digitization, efficiency, and good adaptability to various materials. However, high-quality laser sintering of different materials remains a challenge: ceramic particles are difficult to be sintered due to low absorbance; metallic particles are prone to oxidation; semiconductor particles are difficult to process for performance enhancement due to high stress. In this work, a new approach is proposed that employs an additional Indium Tin Oxide (ITO) sacrificial layer to assist laser sintering of different functional materials, which detaches after sintering without contaminating the target material. As a laser absorber, the ITO layer can raise the sintering temperature up to 2950 K, resulting in well coarsening of ceramic grains. As an oxygen barrier, the ITO layer maintains the oxidation level of the metal die below 25%. As a temperature homogenizer, the ITO layer delays the cracking and improves the performance of the semiconductor material, which in turn increases its Seebeck factor to 1.4-fold. Therefore, the ITO sacrificial layer is a material-friendly, purity-neutral laser sintering strategy, which supports laser sintering of multi-materials and high-performance thin-film devices.