Mesoscale Simulations on Morphology Design in Conjugated Polymers and Inorganic Nanoparticles Composite for Bulk Heterojunction Solar Cells

Abstract

Mixtures of conjugated polymers (CPs) as donors and inorganic semiconducting nanoparticles (NPs) as acceptors are considered to be promising materials for photoactive layers of bulk heterojunction hybrid solar cells (HSCs). To reach the high power conversion efficiency of HSC, the morphology of the photoactive layer for providing optimal charge transport paths is designed. Herein, the coarse‐grained model for predicting the morphology of nanocomposites based on semiconducting CPs and NPs is used. For polymer matrix, well‐known CPs such as poly(3‐hexythiophene) (P3HT), poly [thieno [3,4‐b] thiophene/benzodithiophen] (PTB7), and poly [[2,6′‐4,8‐ di(5‐ethylhexylthienyl)benzo[1,2‐b;3,3‐b] dithiophene][3‐fluoro‐ 2[(2‐ethylhexyl) carbonyl] thieno[3,4‐b]thiophenediyl]] (PTB7‐Th) are selected. For NP fillers, PbS quantum dots modified by ligands (like, e.g., oleic acid) are selected. Via mesoscale computer simulations, it is shown that by choosing appropriate ligands for NPs and varying the weight fraction of NPs, the morphology with bicontinuous charge transport paths for holes and electrons is obtained. Such morphologies are observed in models of homopolymer/NP blends for the first time. This finding is in reasonable agreement with the recent experimental results on these systems.

Two-state nanocomposite based on symmetric diblock copolymer and planar nanoparticles: mesoscopic simulation

“…We have used this method repeatedly in the past as it provides a flexible way to overcome the limitations of the available spatiotemporal scales in modelling polymer nanocomposites, see for example. 47,[70][71][72] The DPD methodology for polymers is described in detail in the following publications [68][69][70] and, for convenience, in Section S1 of the ESI † file. Some details of the terminology used in DPD are given below to allow the reader to better understand the peculiarities of the construction and parameterisation of the model studied.…”