Altering the Thermodynamics of Phase Separation in Inverted Bulk‐Heterojunction Organic Solar Cells

Abstract

Organic solar cells: By incorporating nonvolatile additives into blends of P3HT:PCBM, the efficiencies of inverted bulk‐heterojunction solar cells are improved almost twofold (see figure). These additives selectively partition into the P3HT phase, effectively increasing phase separation between the P3HT and PCBM.

The influence of additive property on performance of organic bulk heterojunction solar cells

“…In conclusion, the additive increasing the hydrophilic-hydrophobic repulsive interactions between donor and acceptor could enhance the scale of phase separation. [54]. C Schematic illustration of a P3HT:PCBM blend film (left) and a P3HT:F-P3HT:PCBM blend film (right), hydrophobic F-P3HT induce phase separation with relatively hydrophilic PCBM preserving the crystallinity of P3HT.…”

“…Transition metal complexes and organic salt which have different hydrophobicity (as shown in Fig. 3B) are employed as additive to improve the morphology of P3HT/PC 61 BM inverted BHJ devices [54]. After the addition of additive, the phase separation characteristics of P3HT and PC 61 BM are enhanced, leading to the formation of more PC 61 BM clusters.…”

“…As a result, the hydrophobic material, such as transition metal complexes, organic salt as shown in Fig. 3A [54] and some functionalized polymer, like hydrophobic end-functionalized P3HT (F-P3HT) [55] are all good candidates to act as this kind of additive. It is obvious that the additive is preferentially segregated in P3HT domains, because of the relatively hydrophobic P3HT.…”

Organic crystallizable solvent served as template for constructing well-ordered PPE films

“…The regular patterned and large-scale films have shown many exciting physical properties, and have been applied in many research fields, such as thin film organic field-effect transistors [1], templates for inorganic nanostructures [2], phononic and photonic crystals, electronic devices [3], magnetic recording devices [4], and biological technologies [5]. The preparation of patterned films has drawing extensive attention during the past decades, and scientists have developed many patterning technologies to manipulate the morphology of well-patterned inorganic, organic and polymer films.…”

Morphological Control Agent in Ternary Blend Bulk Heterojunction Solar Cells

“…Among these additives, the fullerene derivatives take the majority due to its compatibility with host acceptors as well as the established solvent systems, though there were other small molecules that revealed a similar function [53][54][55]. Herein we focus on the development of a variety of kinds of fullerene derivatives as morphological control agents.…”