Upconversion Material-Mediated Semiconductor Bonding

Semiconductor wafer bonding, mediated by upconversion materials, is proposed and demonstrated. Upconversion is a process that converts long wavelength light into short wavelength light, and is expected to be applied to a variety of optoelectronic devices. Bonding with high electrical conductivity and imparting optical properties to the interface is realized by utilizing an adhesive viscous organic matrix with embedded upcinversiion nanoparticles. The application of this method to multijunction solar cells is expected.