Performance Enhancement of Organic Solar Cells by Adding a Liquid Crystalline Molecule in Cathode and Anode Interlayers

Abstract

In this study, an effective and simple approach for optimizing the performance of both cathode and anode interlayers in OSCs is demonstrated using 4-heptyl-4′-cyanobiphenyl (7CB) to dope a classic cathode (ZnO and SnO2) or an anode interlayer [poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate) (PEDOT:PSS)]. Because of the enhanced light absorption, improved physical contact between a photoactive layer and an interlayer, and increased carrier recombination, all of the devices based on a 7CB-doped interlayer show increased short-circuit current density (J sc), fill factor (FF), and power conversion efficiency (PCE) compared to the corresponding undoped interlayer, regardless it is the anode interlayer or the cathode interlayer, which is a rare phenomenon in the interlayer modification field.

Cathode Interface Layer Based on Organosilica Nanodots for Efficient and Stable Inverted Organic Solar Cells

“…When α is close to 1, it indicates that the bimolecular recombination is very weak. The α values of ZnO device and OSi-ErB device were 0.95 and 0.95, respectively …”

“…The α values of ZnO device and OSi-ErB device were 0.95 and 0.95, respectively. 38 Besides high performance, stability is also an important concern for industrial production and practical applications, Figure 4a,b depicts how the J−V performance of wrapped ZnO-based and OSi-ErB-based OSCs changed during the course of 10 h of successive AM 1.5 G irradiation (100 mW cm −2 ). Figure S16 (Supporting Information) shows their normalized PCE change over 10 h. The OSi-ErB device has excellent photostability and still maintains 95% of the initial performance after 10 h of UV light irradiation, while the ZnO device has only 72% of the initial performance.…”

A Cost-Effective Alpha-Fluorinated Bithienyl Benzodithiophene Unit for High-Performance Polymer Donor Material

“…7.03 (d, 1H), 6.78 (d, 1H), 2.51 (d, 2H), 1.66−1.57 (m, 1H), 1.34−1.25 (m, 8H), 0.92−0.84 (m, 6H). 13 C NMR (100 MHz, CDCl 3 ): δ (p.p.m.) 138.…”

“…7.63 (s, 2H), 6.96 (s, 2H), 2.59 (d, 4H), 1.70− 1.60 (m, 2H), 1.47−1.28 (m, 16H), 0.99−0.87 (m, 12H), 0.49−0.32 (m, 18H). 13 The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsami.1c15278.…”

“…Solution-processable polymer solar cells (PSCs) are of wide concern in sunlight utilization because of their intrinsic advantages of a simple device preparation process, lightweight nature, flexibility, and translucency. − At present, the photovoltaic power conversion efficiency (PCE) of the PSCs has exceeded 18%, benefitting from the innovations of photoactive materials, morphology regulation of photoactive layers, and interface layer optimization of the devices. − The photovoltaic performance of PSCs has met the requirements of commercial applications currently. However, most excellent photoactive materials (including donors and acceptors) suffer from excessive synthetic cost owing to the complex chemical structures, prolix synthetic route, low synthetic yield, and difficult multistep purification, , which greatly limit the schedule of PSCs from the laboratory to the factory.…”