Hemispherical-shell-shaped organic photovoltaic cells for absorption enhancement and improved angular coverage

Abstract

A hemispherical shell shape is proposed for an organic photovoltaic cell structure, aiming at enhancing both light absorption and angular coverage. Three-dimensional finite element analysis method is used to study the absorption spectra within the hemispherical-shell-shaped active layer. The study reveals that the proposed structure can result in 66% and 36% of absorption improvements compared to a flatstructured device when the incoming light is transverse electric (TE)-and transverse magnetic (TM)-polarized, respectively. It is also learned that the proposed hemispherical shell structure has absorption improvement as high as 13% (TE) and 21% (TM) when compared to the previously reported semicylindrical shell structure. The angular coverage of the proposed structure is improved as well, reaching 81 deg (TE) and 82 deg (TM), which becomes quite useful for the wearable electronics applications where the incidence angle can vary in a random manner. These improvements can be attributed to better light coupling and guiding through the active layer made possible by the hemispherical shell shape of the device.

Epitaxial Growth of CsPbBr3 Pyramids/CdS Nanobelt Heterostructures for High-Performance Photodetectors

“…It is worth noting that this band alignment will lead to almost no barrier obstruction when electrons move from CsPbBr 3 to CdS (or when holes move from CdS to CsPbBr 3 ), which means that this heterostructure can effectively promote the separation and transfer of photogenerated electrons. According to previous reports, the pyramidal micro–nanostructures on the surface of semiconductors could bring in advantages in diminishing the reflection losses, enhancing the light absorption, and expanding the angular coverage. − Figure a illustrates that the construction of CsPbBr 3 pyramides on CdS nanobelt can enable the incident light to undergo multiple reflections and refractions in the CsPbBr 3 pyramids/CdS nanobelt heterostructure, which is benefit to diminish the reflection losses. Besides, the theoretical simulation demonstrates that the optical waveguide can be achieved and confined within CdS due to the unique morphology of the nanobelt (see Figure b,c).…”