Geometry Design And Model Simulation Of Polymer Solar Cells

In this paper, a geometry—pyramid structure, which can enhance the performance ofpolymer solar cells (PSCs), is studied. Moreover, a numerical device model that describes thecurrent-voltage characteristics of polymer bulk heterojunction solar cells is introduced.PSCs light utilization efficiency is limited as their active layers are always very thin dueto low carrier mobility so much light is just reflected off. By introducing a geometry ofpyramid, a light trap can be formed which can reflect and hence absorb the incident lightmore than one time. So this geometry enhances the power conversion efficiency (PCE)significantly, particularly for the30°pyramid devices，leading a triple PCE compared to aplanar device. This geometry applies to PSCs based both on solid or flexible substrates.Moreover, it can realize a100%space utilization when assembled into large scale devicearrays.Metal-Insulator-Metal model is a well-known numerical model describing thecurrent-voltage characteristics of the bulk heterojunction PSCs. This model depends on thedescription of the active blend layer as one medium, described by basic semiconductorequations. Drift and diffusion of charge carriers, bimolecular recombination and atemperature-and field-dependent generation mechanism of free charges are incorporated.This model helps us get more understanding of the theoretical mechanism inside PSCs.