A high-efficiency ternary organic solar cell

Abstract

The invention discloses a high-efficiency ternary organic solar cell, which includes a substrate, a cathode, a cathode modification layer, an active layer, an anode modification layer and an anode, wherein the active layer is a polymer electron donor PBDB-T and A blend film of two small molecule electron acceptors, HF‑PCIC and IEICO‑4F. Utilizing the complementary absorption of PBDB-T, HF-PCIC and IEICO-4F, especially by means of IEICO-4F to optimize the morphology of the active layer, the ternary organic solar cell prepared by the present invention realizes a wide spectrum of 300-1000nm Good photoelectric response in the range, compared to PBDB‑T:HF‑PCIC-based binary organic solar cells, the improvement of short-circuit current density is up to 7.2mA / cm 2 , the highest power conversion efficiency (PCE) is 11.20%, which is much higher than the 8.82% of the binary battery. In addition, the ternary organic solar cells also exhibited very low energy loss (0.59 eV), resulting in a high open-circuit voltage for the cells.

Description

technical field [0001] The invention relates to a solar cell, in particular to a high-efficiency ternary organic solar cell. Background technique [0002] The active layer of a traditional organic solar cell is a binary blend film composed of an electron donor and an electron acceptor (binary organic solar cell). However, due to the discontinuous energy level structure of organic electron donors and electron acceptors, it is difficult for the binary blend film to obtain a wide and strong spectral absorption range, which limits the absorption and utilization of sunlight by the battery, and the short-circuit current density cannot be achieved. Comparable to inorganic solar cells (such as monocrystalline silicon and polycrystalline silicon solar cells) with continuous energy level structure (energy band). To this end, people add a third component (either an electron donor or an electron acceptor) that is complementary to the absorption of the original binary blend film into th...

AI Technical Summary

Problems solved by technology

Adding the third component to the binary blend film will easily cause damage to the original good morphology and affect the generation and transmission of photogenerated charges, thus limiting the increase in short-circuit current density and efficiency of the battery

On the other hand, in order to broaden the range of light absorption, the third component in the ternary battery must be an electron donor or acceptor with a narrower band gap than the original binary material system, such as a material that absorbs strongly in the near-infrared region. The narrowing of the gap means that the HOMO energy level of the material increases and (or) the LUMO energy level decreases, so it is easy to cause a significant decrease in the open circuit voltage of the battery, which also limits the improvement of the efficiency of the ternary battery.

Therefore, how to greatly increase the short-circuit current density in ternary organic solar cells while maintaining a high open-circuit voltage is a big challenge.

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