Liuyanfeng

Small-molecule nonfullerene-based tandem organic solar cells (OSCs) are fabricated for the first time by utilizing P3HT:SF(DPPB)₄ and PTB7-Th:IEIC bulk heterojunctions as the front and back subcells, respectively. A power conversion efficiency of 8.48% is achieved with an ultrahigh open-circuit voltage of 1.97 V, which is the highest voltage value reported to date among efficient tandem OSCs.

In order to help readers stay up-to-date in the field, each issue of Progress in Photovoltaics will contain a list of recently published journal articles that are most relevant to its aims and scope. This list is drawn from an extremely wide range of journals, including IEEE Journal of Photovoltaics, Solar Energy Materials and Solar Cells, Renewable Energy, Renewable and Sustainable Energy Reviews, Journal of Applied Physics and Applied Physics Letters. To assist readers, the list is separated into broad categories, but please note that these classifications are by no means strict. Also note that inclusion in the list is not an endorsement of a paper's quality. If you have any suggestions, please email Ziv Hameiri at ziv.hameiri@unsw.edu.au. Copyright © 2016 John Wiley & Sons, Ltd.

Organic solar cells hold promise of providing low-cost, renewable power generation, with current devices providing up to 13% power conversion efficiency. The rational design of more performant systems requires an in-depth understanding of the interactions between the electron donating and electron accepting materials within the active layers of these devices. Here, we explore works that give insight into the intermolecular interactions between electron donors and electron acceptors, and the impact of molecular orientations and environment on these interactions. We highlight, from a theoretical standpoint, the effects of intermolecular interactions on the stability of charge carriers at the donor/acceptor interface and in the bulk and how these interactions influence the nature of the charge transfer states as well as the charge separation and charge transport processes.

An assessment of intermolecular interactions and their impact on electronic processes in organic solar cells is presented. While a great deal has been learned about the molecular-scale optical and electronic processes in these devices, a complete understanding of how the active-layer composition and morphology influence the charge transfer states, polarization and charge separation still needs to be reached.

Organic solar cells (OSCs) and organic-inorganic metal halide perovskite solar cells (pero-SCs) have been regarded as two promising photovoltaic technologies. The recent advances with power conversion efficiency over 10% and 20% have been realized in OSCs and pero-SCs, respectively. The fullerene derivatives play important role as acceptor materials in OSCs and cathode buffer layer (CBL) materials in OSCs and pero-SCs. Here, we provide a comprehensive overview of recent progresses and perspectives of the functional fullerene derivatives as acceptor materials and CBLs for OSCs and pero-SCs.

Fullerene derivatives play a very important role as acceptor materials in organic solar cells (OSCs), cathode buffer layer materials in OSCs and perovskite solar cells (pero-SCs). Here, a comprehensive overview of recent progresses and perspectives of functional fullerene derivatives as acceptor materials and buffer layer materials for OSCs and pero-SCs is provided.

A very high hole mobility of 15 cm² V⁻¹ s⁻¹ along with negligible hysteresis are demonstrated in transistors with an organic–inorganic perovskite semiconductor. This high mobility results from the well-developed perovskite crystallites, improved conversion to perovskite, reduced hole trap density, and improved hole injection by employing a top-contact/top-gate structure with surface treatment and MoO_x hole-injection layers.

The aggregation of conjugated polymers is found to have a significant influence on the surface organization of deposited films. Difluorobenzothiadiazole-based polymers show a strong pre-aggregation in solution, but the addition of 1,2,4-trichlorobenzene efficiently reduces such aggregates, leading to the transition of the surface organization from edge- to face-on orientation in deposited films.

Fine energy-level modulations of small-molecule acceptors (SMAs) are realized via subtle chemical modifications on strong electron-withdrawing end-groups. The two new SMAs (IT-M and IT-DM) end-capped by methyl-modified dicycanovinylindan-1-one exhibit upshifted lowest unoccupied molecular orbital (LUMO) levels, and hence higher open-circuit voltages can be observed in the corresponding devices. Finally, a top power conversion efficiency of 12.05% is achieved.

A highly efficient fullerene-free polymer solar cell (PSC) based on PDCBT, a polythiophene derivative substituted with alkoxycarbonyl, achieves an impressive power conversion efficiency of 10.16%, which is the best result in PSCs based on polythiophene derivatives to date. In comparison with a poly(3-hexylthiophene):ITIC-based device, the photovoltaic and morphological properties of the PDCBT:ITIC-based device are carefully investigated and interpreted.

In article 1600032, an efficient new wide-bandgap polymer based on a novel moiety of pyrrolo[3,4-f]benzotriazole-5,7-dione (TZBI) is developed by Lei Ying, Feng Lui, Thomas P. Russel, Fei Huang, and co-workers. The new chemistry enables fine electronic structure tuning and solution-processed single-junction polymer solar cells provided a remarkable power conversion efficiency of 8.63%. Full electrical and structural characterization reveales that TZBI is a promising building block for the application in highly efficient organic photovoltaics.