- Award ID(s):
- 1801317
- NSF-PAR ID:
- 10276914
- Date Published:
- Journal Name:
- Journal of Materials Chemistry C
- ISSN:
- 2050-7526
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
In this work, two new C 70 isomers, α and β bis(2-(thiophen-2-yl)ethyl)-C 70 -fullerene mono-adducts (DTC 70 ), were synthesized, characterized and used as electron transporting materials (ETMs) in perovskite solar cells (PSCs). Our results show that the α isomer improves both the J sc and FF values of the devices, when compared to the results for the β-isomer and to those for phenyl-C 70 -butyric acid methyl ester ( PC71BM ), used as control. Devices based on α-DTC70 achieved a power conversion efficiency (PCE) of 15.9%, which is higher than that observed with PC71BM (15.1%).more » « less
-
Abstract Two cove‐edge graphene nanoribbons hPDI2‐Pyr‐hPDI2 (
1 ) and hPDI3‐Pyr‐hPDI3 (2 ) are used as efficient electron‐transporting materials (ETMs) in inverted planar perovskite solar cells (PSCs). Devices based on the new graphene nanoribbons exhibit maximum power‐conversion efficiencies (PCEs) of 15.6 % and 16.5 % for1 and2 , respectively, while a maximum PCE of 14.9 % is achieved with devices based on [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM). The interfacial effects induced by these new materials are studied using photoluminescence (PL), and we find that1 and2 act as efficient electron‐extraction materials. Additionally, compared with PC61BM, these new materials are more hydrophobic and have slightly higher LUMO energy levels, thus providing better device performance and higher device stability. -
Abstract Two cove‐edge graphene nanoribbons hPDI2‐Pyr‐hPDI2 (
1 ) and hPDI3‐Pyr‐hPDI3 (2 ) are used as efficient electron‐transporting materials (ETMs) in inverted planar perovskite solar cells (PSCs). Devices based on the new graphene nanoribbons exhibit maximum power‐conversion efficiencies (PCEs) of 15.6 % and 16.5 % for1 and2 , respectively, while a maximum PCE of 14.9 % is achieved with devices based on [6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM). The interfacial effects induced by these new materials are studied using photoluminescence (PL), and we find that1 and2 act as efficient electron‐extraction materials. Additionally, compared with PC61BM, these new materials are more hydrophobic and have slightly higher LUMO energy levels, thus providing better device performance and higher device stability. -
Abstract Flexible perovskite solar cells (
f ‐PSCs) have attracted great attention due to their promising commercial prospects. However, the performance off ‐PSCs is generally worse than that of their rigid counterparts. Herein, it is found that the unsatisfactory performance of planar heterojunction (PHJ)f ‐PSCs can be attributed to the undesirable morphology of electron transport layer (ETL), which results from the rough surface of the flexible substrate. Precise control over the thickness and morphology of ETL tin dioxide (SnO2) not only reduces the reflectance of the indium tin oxide (ITO) on polyethylene 2,6‐naphthalate (PEN) substrate and enhances photon collection, but also decreases the trap‐state densities of perovskite films and the charge transfer resistance, leading to a great enhancement of device performance. Consequently, thef ‐PSCs, with a structure of PEN/ITO/SnO2/perovskite/Spiro‐OMeTAD/Ag, exhibit a power conversion efficiency (PCE) up to 19.51% and a steady output of 19.01%. Furthermore, thef ‐PSCs show a robust bending resistance and maintain about 95% of initial PCE after 6000 bending cycles at a bending radius of 8 mm, and they present an outstanding long‐term stability and retain about 90% of the initial performance after >1000 h storage in air (10% relative humidity) without encapsulation. -
Abstract Electron transport layer (ETL) is a functional layer of great significance for boosting the power conversion efficiency (PCE) of perovskite solar cells (PSCs). To date, it is still a challenge to simultaneously reduce the surface defects and improve the crystallinity in ETLs during their low‐temperature processing. Here, a novel strategy for the mediation of in situ regrowth of SnO2nanocrystal ETLs is reported: introduction of controlled trace amounts of surface absorbed water on the fluorinated tin oxide (FTO) or indium–tin oxide (ITO) surfaces of the substrates using ultraviolet ozone (UVO) pretreatment. The optimum amount of adsorbed water plays a key role in balancing the hydrolysis–condensation reactions during the structural evolution of SnO2thin films. This new approach results in a full‐coverage SnO2ETL with a desirable morphology and crystallinity for superior optical and electrical properties, as compared to the control SnO2ETL without the UVO pretreatment. Finally, the rigid and flexible PSC devices based on the new SnO2ETLs yield high PCEs of up to 20.5% and 17.5%, respectively.