阅读说明：本技术 一种基于非富勒烯受体合金的高效三元有机太阳电池 (Efficient ternary organic solar cell based on non-fullerene acceptor alloy ) 是由 陈红征 占玲玲 李水兴 施敏敏 李寒莹 于 2019-10-09 设计创作，主要内容包括：本发明公开了一种基于非富勒烯受体合金的高效三元有机太阳电池,它包括衬底、阳极、阳极修饰层、活性层、阴极修饰层和阴极,其中活性层为聚合物给体PM6与非富勒烯受体合金的共混膜,而非富勒烯受体合金是由二种非富勒烯受体Y6和BTP-M按一定比例混合而成的Y6:BTP-M合金。利用BTP-M相对于Y6更高的能级和更弱的结晶性,Y6:BTP-M合金同时优化了活性层的能级和形貌,从而使PM6:Y6:BTP-M三元有机太阳电池获得比PM6:Y6二元电池更大的电压和电流,并最终实现了目前单结有机太阳电池最高的能量转换效率(PCE＝17.03％)。此外,该三元有机太阳电池的性能对活性层厚度不敏感,在活性层厚度为120-300nm时,PCE均在14％以上。(The invention discloses a non-fullerene receptor alloy-based efficient ternary organic solar cell, which comprises a substrate, an anode modification layer, an active layer, a cathode modification layer and a cathode, wherein the active layer is a blend film of a polymer donor PM6 and a non-fullerene receptor alloy, and the non-fullerene receptor alloy is a Y6: BTP-M alloy formed by mixing two non-fullerene receptors Y6 and BTP-M according to a certain proportion. By utilizing higher energy level and weaker crystallinity of BTP-M relative to Y6, the Y6: BTP-M alloy simultaneously optimizes the energy level and morphology of an active layer, so that the PM6: Y6: BTP-M ternary organic solar cell obtains larger voltage and current than the PM6: Y6 binary cell, and finally achieves the highest energy conversion efficiency (PCE is 17.03%) of the current single-junction organic solar cell. In addition, the performance of the ternary organic solar cell is insensitive to the thickness of the active layer, and when the thickness of the active layer is 120-300nm, the PCE is more than 14%.)

1. A high-efficiency ternary organic solar cell based on non-fullerene acceptor alloy comprises a substrate, an anode modification layer, an active layer, a cathode modification layer and a cathode, and is characterized in that the active layer is a blended film of an electron donor and the non-fullerene acceptor alloy.

2. The efficient ternary organic solar cell based on non-fullerene acceptor alloy as claimed in claim 1, wherein the electron donor is polymer donor PM6, the non-fullerene acceptor alloy is Y6: BTP-M alloy formed by mixing two non-fullerene acceptors Y6 and BTP-M according to a certain proportion, and the chemical structural formulas of the corresponding donor and non-fullerene acceptor are as follows:

。

3. the efficient ternary organic solar cell based on non-fullerene acceptor alloy as claimed in claim 1 or 2, wherein the weight ratio of PM6 to Y6: BTP-M alloy in the active layer is 2: 1-1: 2, the ratio of BTP-M in the total weight of Y6: BTP-M alloy is 10-30%, and the thickness of the active layer is 50-500 nm.

4. The efficient ternary organic solar cell based on a non-fullerene acceptor alloy according to claim 1, wherein the active layer is prepared by film formation of an active layer solution containing the electron donor and the non-fullerene acceptor alloy, an additive is added during film formation, the additive is Chloronaphthalene (CN) or 1, 8-Diiodooctane (DIO), and the volume of the additive is 0.2-2% of the volume of the active layer solution.

5. The efficient ternary organic solar cell based on a non-fullerene acceptor alloy as claimed in claim 1, wherein the active layer is annealed at 80-200 ℃ for 5-60 min.

6. The non-fullerene acceptor alloy-based high efficiency ternary organic solar cell according to claim 1, wherein: the substrate is glass; the anode is ITO; the anode modification layer is PEDOT, PSS; the cathode modification layer is PFN-Br; the cathode is Ag.

Technical Field

The invention relates to a solar cell, in particular to a high-efficiency ternary organic solar cell based on a non-fullerene acceptor alloy.

Background

Organic solar cells have gained rapid improvements in energy conversion efficiency (PCE) in recent years with the rapid development of non-fullerene receptors. In particular, a non-fullerene acceptor Y6 developed by a Duckweed subject group in Zhongnan university has a narrow band gap, a photovoltaic response range can be widened to about 930nm, and meanwhile, Y6 has strong crystallinity and improves the electron mobility, so that Y6 is matched with a polymer donor PM6, and the PCE of the obtained binary organic solar cell breaks through 15% (Joule,2019,3,1140) and the progress of the organic solar cell is strongly promoted.

The ternary organic solar cell is constructed by adding the third component, and is an effective way for further improving the energy conversion efficiency. For example, the Gezi theme group of Ningbo materials of Chinese academy of sciences is that a fullerene acceptor PC is added into a PM6: Y6 binary organic solar cell₇₁BM enhances the absorption of the battery in the range of 300-500nm and optimizes the morphology of an active layer, PM6: Y6: PC₇₁The PCE of BM ternary organic solar cells reached 16.67%, which was the highest efficiency of unijunction organic solar cells at that time (Advanced Materials,2019,1902210). However, due to the inherent disadvantages of weak absorption, difficult adjustment of energy levels, and poor compatibility with non-fullerene receptors, fullerene receptors have limited performance improvements for binary non-fullerene cells (NatPhotonics,2015,9, 190). On the contrary, because the non-fullerene receptor has abundant chemical structure changes, the light absorption range, the energy level and the aggregation state structure of the non-fullerene receptor can be greatly regulated, so that the introduction of a second non-fullerene receptor into the binary non-fullerene cell can theoretically realize the wider and more precise improvement of the light absorption, the energy level and the morphology of the active layer, thereby obtaining higher PCE. Unfortunately, it is still rarely reported that over 16% or even more efficient work can be achieved by adding a second non-fullerene acceptor to the binary system PM6: Y6.

On the other hand, the organic solar cell prepared by the industrialized technology, such as the roll-to-roll printing technology, cannot realize the precise control of the thickness of the active layer, and the thickness of the organic solar cell fluctuates in a range of tens to hundreds, so that the organic solar cell with insensitive photovoltaic performance to the thickness is obtained, and the method is significant for the future industrialized application. The organic solar cell insensitive to the thickness needs to well regulate and control the morphology of an active layer, ensures high crystallinity to be beneficial to carrier transmission, and obtains high exciton separation efficiency by virtue of small phase separation size, thereby being a challenging problem. The preparation of a ternary non-fullerene cell by adding a second non-fullerene acceptor is a theoretically feasible approach, but at present, no literature report is available on a ternary non-fullerene cell with the active layer thickness in the range of 100-300nm and the PCE of more than 14%.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a ternary organic solar cell with high efficiency and insensitivity to the thickness of an active layer.

The efficient ternary organic solar cell based on the non-fullerene acceptor alloy comprises a substrate, an anode modification layer, an active layer, a cathode modification layer and a cathode, and is characterized in that the active layer is a blended film of an electron donor and the non-fullerene acceptor alloy.

The electron donor is a polymer donor PM6, the non-fullerene acceptor alloy is a Y6: BTP-M alloy formed by mixing two non-fullerene acceptors Y6 and BTP-M according to a certain proportion, and the chemical structural formulas of the corresponding donor and the non-fullerene acceptor are as follows:

the weight ratio of PM6 to Y6 to BTP-M alloy in the active layer is 2: 1-1: 2, the proportion of BTP-M in the total weight of Y6 to BTP-M alloy is 10-30%, and the thickness of the active layer is 50-500 nm.

The active layer is prepared by adopting an active layer solution containing the electron donor and non-fullerene acceptor alloy to form a film, an additive is added during film forming, the additive is Chloronaphthalene (CN) or 1, 8-Diiodooctane (DIO), and the volume of the additive is 0.2-2% of the volume of the active layer solution.

The active layer is annealed at the temperature of 80-200 ℃ for 5-60 min.

The substrate is glass; the anode is ITO; the anode modification layer is PEDOT, PSS; the cathode modification layer is PFN-Br; the cathode is Ag.

The invention has the advantages that the invention adopts Y6 BTP-M alloy which is formed by mixing two non-fullerene receptors Y6 and BTP-M according to a certain proportion as an electron receptor, and integrates the respective advantages of the two materials: y6 has wide light absorption range, strong crystallinity, high electron mobility, but large phase separation size, and BTP-M has weak crystallinity, low electron mobility, but small phase separation size, and can improve exciton separation efficiency, and the LUMO energy level of BTP-M is high, which is beneficial to improving the open-circuit voltage of the battery. Therefore, the invention utilizes the non-fullerene receptors with similar chemical structures, good intersolubility and obvious photoelectric property difference of Y6 and BTP-M to prepare the alloy, and the alloy is blended with the polymer donor PM6 to realize good regulation and control of the energy level and the morphology of the active layer, so that the energy level of the electron receptor is high, and the morphology is simultaneously beneficial to exciton separation and carrier transmission. Due to the advantages, the PM6: Y6: BTP-M ternary organic solar cell prepared by the invention obtains larger voltage and current than the PM6: Y6 binary cell, and finally achieves one of the highest energy conversion efficiencies (PCE is 17.03%) of the current unijunction organic solar cell. In addition, the performance of the ternary organic solar cell is insensitive to the thickness of the active layer, and the energy conversion efficiency of the device reaches 14.23% under the thickness of the active layer of 300 nm.

Drawings

FIG. 1 synthetic route to BTP-M

FIG. 2 DSC curves of Y6, BTP-M and Y6: BTP-M (weight ratio 4:1) alloys

FIG. 3 CV curves for alloys of Y6, BTP-M and Y6: BTP-M (weight ratio 4:1)

eEQE spectrum of ternary organic solar cell in FIG. 4

FIG. 5 is a current-voltage curve of a thin film ternary organic solar cell under illumination. The thickness of the active layer of the battery is about 120nm, Chloronaphthalene (CN) accounting for 0.5 percent of the volume of the solution of the active layer is added during preparation, the total weight ratio of PM6 to non-fullerene acceptor alloy (Y6 and BTP-M) in the active layer is 1:1.2, wherein the proportion of the BTP-M in the non-fullerene acceptor alloy is changed from 0 percent to 100 percent, and the battery is subjected to annealing treatment at 100 ℃ for 10 min.

Fig. 6 current-voltage curves of thick film ternary organic solar cells under light. The thickness of the active layer of the battery is changed from 120nm to 400nm, Chloronaphthalene (CN) accounting for 0.5 percent of the volume of the solution of the active layer is added during preparation, the total weight ratio of PM6 to non-fullerene acceptor alloy (Y6 and BTP-M) in the active layer is 1:1.2, wherein the ratio of BTP-M to non-fullerene acceptor alloy is 20 percent, and the battery is subjected to annealing treatment at 100 ℃ for 10 min.

Detailed Description