11.4% Efficiency non-fullerene polymer solar cells with trialkylsilyl substituted 2D-conjugated polymer as donor

Abstract

Simutaneously high open circuit voltage and high short circuit current density is a big challenge for achieving high efficiency polymer solar cells due to the excitonic nature of organic semdonductors. Herein, we developed a trialkylsilyl substituted 2D-conjugated polymer with the highest occupied molecular orbital level down-shifted by Si–C bond interaction. The polymer solar cells obtained by pairing this polymer with a non-fullerene acceptor demonstrated a high power conversion efficiency of 11.41% with both high open circuit voltage of 0.94 V and high short circuit current density of 17.32 mA cm−2 benefitted from the complementary absorption of the donor and acceptor, and the high hole transfer efficiency from acceptor to donor although the highest occupied molecular orbital level difference between the donor and acceptor is only 0.11 eV. The results indicate that the alkylsilyl substitution is an effective way in designing high performance conjugated polymer photovoltaic materials.

Environmentally-friendly solvent processed fullerene-free organic solar cells enabled by screening halogen-free solvent additives

“…Great efforts have been made to improve the power conversion effi-ciencies (PCEs) of OSCs by utilizing novel materials and new processing methods over the past decades [1,[20][21][22][23][24][25][26][27][28][29][30][31]. Recently, high-performance non-fullerene acceptor materials, especially the small-molecular acceptors (SMAs), were successfully developed [32][33][34][35][36][37][38][39][40][41][42][43][44][45].…”

A Near‐Infrared Photoactive Morphology Modifier Leads to Significant Current Improvement and Energy Loss Mitigation for Ternary Organic Solar Cells

“…In particular with the advantages of strong light‐harvesting capability and ease energy level tunability,8, 9, 10, 11, 12, 13, 14 OSCs employing nonfullerene acceptors have made breakthroughs of power conversion efficiencies (PCEs) over 13% 15, 16, 17, 18. Though OSCs with the binary blend of a donor and an acceptor as the active layer develop rapidly, there still exist some drawbacks, e.g., limited absorption range for two materials, restricted morphological optimization.…”

Enhanced power conversion efficiency in iridium complex-based terpolymers for polymer solar cells

“…Among many different materials categories, fluorinated-thieno [3,4-b] thiophene-based PTB7 and PTB7-Th and derivatives have proven to be excellent candidates. 3,[10][11][12][13] (ii) To overcome the shortcomings of fullerenes, such as weak absorption in the solar spectrum range, limited structural and energy level variability as well as device instability of the most widely used fullerene acceptors, the exploration of high performance new non-fullerene electron acceptors which comprise electron-deficient building blocks with low-lying HOMO and lowest unoccupied molecular orbital energy levels, strong absorption and high electron mobilities finds increasing attention in the field of OSCs. [14][15][16][17][18][19] (iii) The involvement of suitable anode or cathode interface materials to reduce the interfacial energy barriers and facilitate an efficient hole or electron extraction from the active layer have also been demonstrated as effective approaches to enhance the PCE.…”