Engineering Non-fullerene Acceptors as a Mechanism to Control Film Morphology and Energy Loss in Organic Solar Cells

Abstract

Solution processable thin-film organic solar cells (TFOSCs) have attracted a lot of research attention in the past few decades, in the search for low-cost, flexible, and portable solar panels. In light of this, tremendous progress has been made in terms of improving materials design, device architecture, and ease of device fabrication processes. The choice of the donor and acceptor materials in the preparation of a polymer blend bulk heterojunction (BHJ) solar absorber medium is of great importance to the overall performance of organic solar cells (OSCs). The limitation in tuning the energy band structures of fullerene molecules poses significant challenges to the progress in BHJ organic solar cells. In an attempt to cater to the challenges, small-molecule non-fullerene acceptors (NFAs) came into the OSC research space with the possibility of altering the optoelectronic properties of the polymer molecules that bring OSCs closer to the realization of full-scale commercialization. This review discusses the role of NFAs in improving film morphology and reducing energy loss in TFOSCs. The recent development in engineering non-fullerene acceptors for solar energy conversion is presented and discussed in terms of reducing energy loss, improving solar cell performances.

Silver decorated magnesium doped photoactive layer for improved collection of photo‐generated current in polymer solar cell

“…The chemicals used in the synthesis of Ag:Mg BMNPs are silver nitrate Ag (>99.5% NO 2 ) 3 , magnesium nitrate hexahydrate Mg(NO 3 ) 2 6H 2 O (≥99.0%), and sodium hydroxide (>99.98% NaBH 4 ), which are purchased from commercial source and used without further processing. Electron donor poly(3-hexylthiophene) (P3HT), and electron acceptor [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) were used as a photoactive layer in the BHJ system; poly(3,4-ethylene-dioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), and chloroform solvent were purchased from Sigma Aldrich.…”

“…4,5 The power conversion efficiency (PCE) of solution-processed thin film solar cell technologies dramatically increased in recent years from less than 10% 7 years ago to nearly 20% using non-fullerene acceptor based solar cells. 6,7 However, the PCE values of fullerene-based solar cells is still lower than that of non-fullerene based OSC because of the limitations of fullerene molecules in terms of narrow optical absorption band, poor energy level tunability, and poor morphology of the absorber film. 8,9 To address some of the challenges in fullerene based OSC, researchers employed functional metal nanoparticles (NPs) and plasmonic metal nanoparticles at different functional layers of the device structure, such as the photo-active layer or/and in the charge transport layers, which are beneficial in increasing the optical path lengths of the incident photons and harvest more photocurrent in TFOSCs.…”

Bulk heterojunction organic photovoltaic cells based on D–A type BODIPY small molecules as non-fullerene acceptors

“…In this regard, non-fullerene small molecule acceptors (NFSMAs) have shown significant advantages due to their low synthesis cost, strong absorption of the solar spectrum in the visible region, higher stability, easy adjustable energy levels, and higher open circuit voltage over fullerenebased acceptor materials. [17][18][19][20][21][22][23][24][25][26][27] Since Zhan et al synthesized a non-fullerene receptor material called ITIC in 2015, 28 the energy conversion efficiency of organic photovoltaic (OPV) cells based on non-fullerene acceptor materials has been continuously making breakthroughs, which further promoted the development of non-fullerene acceptors (NFAs) having an acceptordonor-acceptor (A-D-A) structure [29][30][31][32] with an optimized power conversion efficiency (PCE) in the range of 12-15%. In 2019, Zou et al reported a novel narrow-band gap star acceptor molecule, Y6, and the OPV devices based on Y6 further achieved a PCE exceeding 15%.…”

Quantitative Prediction of Charge Mobilities and Theoretical Insight into the Regulation of Site-Specific Trifluoromethylethynyl Substitution to Electronic and Charge Transport Properties of 9,10-Anthraquinone

“…Organic semiconductor materials play a significant role in various fields such as bioelectronics, , organic solar cells, − optoelectronic devices, , and biological sensors. , In the past decade, considerable attention was devoted to n-type semiconductors because of their wide-ranging applications in electronic devices, such as n-channel organic field-effect transistors (OFETs) and organic light-emitting diodes (OLEDs). − Nevertheless, the development of n-type semiconductors has largely lagged behind that of the p-type counterparts, which has limited the development of practical organic electronics. , The principal challenges for the n-channel semiconductors are their ambient instability and low electron mobility. Recently, some strategies have been introduced to optimize the electron transport layer for better ambient stability, such as lowering frontier molecular orbital (FMO) energies or introducing kinetic O 2 /H 2 O barriers .…”