I Have a Research Support System

It was almost eleven o'clock when the processing was completed.

Xu Qiu returned to A501 and sat on the sofa thinking.

There is also a bathroom on Zhang Jiang's side, but there is no change of clothes and toiletries.

There is no other way but to make do with it for one night.

After a brief wash, his eyes turned to the bed in the office. The sheets and quilt were relatively clean, and they probably hadn't been used a few times.

Xu Qiu locked the door, turned off the lights, lay on the bed, did not enter the simulation laboratory, and soon fell asleep.

Today's literature reading and physical exercise tasks are not neglected to complete.

It's really tiring.

From one o'clock in the afternoon to eleven o'clock in the evening, for ten consecutive hours, except for drinking two sips of water, going to the toilet, and eating a meal, I never stopped.

It is said that scientific research is mental work, but this is physical work.

...

The next day, Xu Qiu got up early in the morning and returned to the laboratory to start the experiment after having breakfast in the Zhangjiang cafeteria.

Putting on the protective equipment, he walked to the fume hood, lifted the aluminum foil outside each reaction vessel, and checked the polymerization reaction.

Consistent with expectations, the reaction time of about 12 hours, several polymerization reactions have almost been carried out.

However, one of the three reaction bottles of the senior sister did not seem to work well, because no solid matter was precipitated in the reaction bottle.

This response was one of the two responses that the senior sister voted for herself, not Xu Qiu's vote for her.

He guessed that the material ratio of the feed was not 1:1, or that the catalyst was deactivated due to the leakage of oxygen into the reaction vessel.

This is also normal. The polymerization reaction requires a very high material ratio, and the catalyst is also very fragile. In many cases, it is difficult to judge which step has a problem, which leads to the failure of the experiment.

Xu Qiu carefully checked his own two systems, PBT4T and P2FBT4T.

The former is similar to the results he observed in the simulation laboratory before, while the latter precipitates a lot of solid matter, which doesn't look normal.

At the beginning, he decided to use this 2TBT unit, that is, a unit with two fluorine atoms connected to the BT unit, mainly based on the experience summarized in the literature.

In order to ensure as few variables as possible, except for the introduction of two fluorine atoms, other conditions were not changed, including the number and position of branched chains and so on.

According to the existing literature reports, the introduction of fluorine atoms in the polymer donor has a high probability of improving its photoelectric performance.

Researchers often report individual cases and describe the advantages of introducing fluorine atoms from the perspective of experimental results.

For example, it can improve the light absorption coefficient of the material, increase the carrier mobility, improve the morphology of the blended film, and so on.

However, no one has explained the role of fluorine atoms theoretically or at the molecular level.

It is still not clear what kind of system is suitable for the introduction of fluorine atoms.

However, this is also normal. Experimental science itself is mainly based on experience. Many problems cannot be explained, so they can be used directly as theorems.

According to Xu Qiu's rough statistics, more than 90% of the systems have improved performance after adding fluorine atoms, and the extent of improvement varies.

Of course, it may not reach 90% in reality, because there must be many systems whose performance is reduced after adding fluorine atoms, and such articles have not been published.

What is the result of your own, you still need to experiment to know.

But at present, it seems that there are some problems.

The solubility of P2TBT4T is also too low.

But no matter what, the experiment still has to continue. The product is completely processed, the device is prepared, and the performance is tested. The result will naturally be known.

...

Xu Qiu added capping agent to the five reaction bottles of the third batch of reactions to start the capping reaction.

Then he returned to A501, turned on the computer, and prepared to search for documents.

There are still a lot of literature in the field of organic photovoltaics. Even if Xu Qiu only reads the literature in the first and second districts, there are dozens of papers a month.

In a hot field like perovskite, there can even be hundreds of papers a month.

With such a large number of documents, it is unrealistic to expect to remember all the content in the documents. If the time interval is long, you can only remember a rough idea.

Moreover, he will only read the summary and conclusion of most of the literature and look at the pictures. He will only read the whole article if it is published in a top journal or if he is very interested in the content.

To find some experimental details this time, we need to re-read the literature.

Fortunately, "the predecessors planted trees, and the descendants enjoyed the shade".

Before printing out the literature, Mr. Wei will also read the literature, summarize the abstract, conclusion, and citation format of the literature, and put them in the WORD document according to the categories.

At the same time, in order to ensure that his students read the documents carefully, he will send them paper documents, and ask them to go to his office to explain the main content of the documents to him after reading the documents, and sometimes ask some questions .

Moreover, he also asked students to sort out the electronic documents, put the screenshots of the article titles, the pictures and tables in the text, and other noteworthy points in one or several pages of PPT, and mark the citation format of the documents for convenience. Find it later.

The previous literature in the field of organic photovoltaics was taught by the senior sister, and she was also responsible for organizing the PPT.

...

For polymer donor materials, the main chain is a long conjugated structure, usually a conjugated aromatic ring, such as a benzene ring or a thiophene ring.

The conjugated structure of the main chain can conduct positively charged holes very well.

In layman's terms, the main chain is like a "wire", along which the holes will transfer from the inside of the film to the surface of the electrode, and then be collected by the electrode to generate current.

The part outside the main chain of the polymer is called a branch chain, which is usually an alkyl side chain, which is non-conductive and can be understood as the insulating rubber skin outside the "wire".

However, the main function of this layer of insulating skin is not for insulation, but to make the polymer material soluble in solvents, facilitate solvent processing, and spin-coat to form a film.

If the branch chain is too large or too many, it will reduce the photoelectric performance of the material.

This is because in the active layer, electron/hole pairs must be split at the interface where the donor and acceptor are in contact to form free electron and hole carriers.

If the donor is really covered like a wire, the donor and the acceptor will not be in contact, and there will be no way to form free electrons and hole carriers, and there will be no way to generate current.

Therefore, under the premise of ensuring the solubility of the polymer donor material, the branched chain should not be too long.

...

Xu Qiu opened the WORD and PPT files they had organized.

First, search in WORD for polymer donor materials with fluorine (F) atoms, and then find the corresponding articles in PPT, and check the titles and pictures initially.

If it is worth reading the text, find the corresponding document in PDF format and read the full text.

Xu Qiu mainly looked at researchers comparing similar polymer donor materials with and without fluorine atoms.

It was found that the polymer donor materials reported by other researchers with multiple fluorine atoms usually choose longer alkyl branched chains, generally a few to a dozen more carbon atoms than those without fluorine atoms.

In his synthesis reaction this time, he did not modify the number of carbon atoms in the branched chain.

Perhaps this is why the product is less soluble?

Thank you Lan Shiyu for the 1000 point reward.