Method and apparatus for light absorption and charged carrier transport

Abstract

Embodiments of the invention pertain to the use of alloyed semiconductor nanocrystals for use in solar cells. The use of alloyed semiconductor nanocrystals offers materials that have a flexible stoichiometry. The alloyed semiconductor may be a ternary semiconductor alloy, such as ABC or ABC, or a quaternary semiconductor alloy, such as ABCD, ABCDor ABCD(where A, B, C, and D are different elements). In general, alloys with more than four elements can be used as well, although it can be much harder to control the synthesis and quality of such materials. Embodiments of the invention pertain to solar cells having a layer incorporating two or more organic materials such that percolated paths for one or both molecular species are created. Specific embodiments of the invention pertain to a method for fabricating nanostructured bulk heterojunction that facilitates both efficient exciton diffusion and charge transport. Embodiments of the subject invention pertain to a solar cell having an architecture that allows for efficient harvesting of solar energy. The organic solar cell architecture can incorporate a host/guest (or matrix/dopant) material system that utilizes the long diffusion lengths for triplet excitons without compromising light absorption efficiency.