Fig. 1

Cross-sectional diagram of a planar solar cell and b orthogonal solar cell. As illustrated, in the case of planar solar cells, photocarrier collection path is in the same direction as the light path. However, orthogonal solar cells allow the photocarrier’s collection path to be decoupled, in this case perpendicularly, from the optical path. This makes it possible to use a thin photoabsorber layer, for enhance the collection efficiency, while maintaining the necessary length of optical path to prevent losses associated with incomplete light absorption