Patent ID: 9103978
Filing Date: 2015-08-11
Classification: G01J,G02B,H01L,Y02E

Abstract:
1. A light-trapping sheet comprising: a plurality of light-transmitting sheets each having first and second principal surfaces, the plurality of light-transmitting sheets being in contact with an environmental medium; and a plurality of light-coupling structures arranged in an inner portion of each of the plurality of light-transmitting sheets at a first and second distance from the first and second principal surfaces, respectively, wherein: each of the plurality of light-coupling structures includes a first light-transmitting layer, a second light-transmitting layer, and a third light-transmitting layer sandwiched therebetween; and a refractive index of the first and second light-transmitting layers is smaller than a refractive index of the light-transmitting sheet; a refractive index of the third light-transmitting layer is larger than the refractive index of the first and second light-transmitting layers; and the third light-transmitting layer has a diffraction grating parallel to the first and second principal surfaces of the light-transmitting sheet, wherein the plurality of light-coupling structures include a first light-coupling structure and a second light-coupling structure two-dimensionally arranged next to each other on a surface parallel to the first and second principal surfaces, and the first and second light-transmitting layer of the first light-coupling structure and the first and second light-transmitting layer of the second light-coupling structure are spaced apart from each other.