The third objective , efficient design , involved sandwiching the nanostructured bismuth telluride between two copper plates and then enclosing the upper plate ( the one coated with the light-absorbing oxides ) and the bismuth telluride in a vacuum .

第三个目标是高效的设计，它涉及到把纳米级的碲化铋夹在两片铜薄片之间然后把位于上方的薄片（这个薄片被覆盖上了吸收光线的氧化物）和碲化铋封入一个真空内。