Thin film structures and devices with integrated light and heat blocking layers for laser patterning

Abstract

Selective removal of specified layers of thin film structures and devices, such as solar cells, electrochromics, and thin film batteries, by laser direct patterning is achieved by including heat and light blocking layers in the device/structure stack immediately adjacent to the specified layers which are to be removed by laser ablation. The light blocking layer is a layer of metal that absorbs or reflects a portion of the laser energy penetrating through the dielectric/semiconductor layers and the heat blocking layer is a conductive layer with thermal diffusivity low enough to reduce heat flow into underlying metal layer(s), such that the temperature of the underlying metal layer(s) does not reach the melting temperature, T, or in some embodiments does not reach (T)/3, of the underlying metal layer(s) during laser direct patterning.