I Have a Research Support System

On Wednesday, Chen Wanqing was still doing synthesis in Zhangjiang. Her molecular synthesis process was not very smooth. The hydrogen extraction reaction of n-butyllithium at low temperature failed once in the middle, so it took longer than expected.

And Han Jiaying and Wu Shengnan had completed their respective experiments the day before, so they stayed in Handan Laboratory today.

The school girl got the final polymerization product, judging by the precipitation state of the polymer in the poor solvent methanol, there is a high probability that the synthesis was successful, and the molecular weight is not low.

She obtained a total of three polymer donor materials, all based on FTAZ units, the names are P-BDTO-FTAZ, P-BDTS-FTAZ, P-BDTT-FTAZ, which respectively use alkoxy side chains, alkylthio The side chains of the BDT unit and the side chain of the alkylthiophene, the FTAZ unit were not modified.

These new molecules were named H11, H12, H13 by her in turn. Among them, "H" is the abbreviation of the surname, the first "1" represents the first generation, and the following "123" is the serial number. If the subsequent development continues, the naming will be H21, H33 and the like...

According to her previous idea, Wu Shengnan tried to prepare perovskite quantum dots by hot injection method, but it was still not smooth, and the reaction product was turbid. However, she successfully synthesized two conjugated polymers P(TPACO) and P(TCEC), so there is no further synthesis of quantum dots.

Different scientific researchers have different naming habits for the materials they develop. For example, Wu Shengnan prefers to use brackets, while in Teacher Wei's research group, influenced by Wei Xingsi, Xu Qiu and the others all prefer to use a horizontal bar "-".

Speaking of this horizontal bar, the "-" in the article is not directly typed with the minus sign on the keyboard, but inserted in the column of special symbols in WORD. The horizontal bar in this special symbol is larger than normal The minus sign for is a little longer, and there's more than one kind.

As for how Xu Qiu found out, it all depends on Mr. Wei's persistence in details, but he personally feels that this is the same as the "four ways of writing fennel beans", and it doesn't have much practical significance.

At 9:30 in the morning, Han Jiaying went to the spin coating glove box to check the solution prepared yesterday.

A total of nine groups, based on her newly synthesized three donors and three acceptors, paired three times three each.

Among them, the three receptors include two previously developed non-fullerene receptors, the third-generation B4T-8 series 3D-PDI molecules of Xuemei, and the IDT-ICIN molecules of Xuemei, as well as fullerene derivatives Receptor PC[70]BM, as a standard.

Because the polymerization products are all extracted by chloroform, the solubility is very good, and there are no large particles of insoluble matter, solid matter hanging on the wall, etc.

After judging that the solution was normal, the school girl began to prepare the zinc oxide substrate.

Wu Shengnan approached Xu Qiu and asked, "Can you teach me to test TRPL?"

Xu Qiu wrote a thesis for two consecutive days before, and wanted to change his taste and do experiments, so he directly agreed: "Yes, when will I test it."

"Now, my samples are all ready." Wu Shengnan obviously came prepared, and she pointed in the direction of the laboratory table, on which there was a petri dish with samples.

"Okay." Xu Qiu nodded. Although the scoring ball did not arrive, the regular TRPL can still be tested.

The two put on gloves, took samples and tweezers tools, entered 218 together, greeted Teacher Wei, started the instrument, and started the test.

Xu Qiu demonstrated once, described the entire operation process, and then watched Wu Shengnan operate it twice.

There are no mistakes, and the basic scientific research literacy of the postdoctoral seniors is still there.

After the teaching was completed, Xu Qiu did not participate in Wu Shengnan's remaining tests.

He went straight back to 216, and heard a call from Han Jiaying from a distance: "Brother, can you help me apply the effective layer~"

"Okay—" Xu Qiu replied through the air, then walked straight into the laboratory, and while wearing a lab coat, asked casually, "How many devices are you going to make?"

In the process of device preparation, the most critical step is the spin coating of the effective layer. Among the organic trio in the laboratory, Xu Qiu considers himself the strongest in terms of spin coating skills, which is why he took the initiative to take over the device preparation. .

"A total of 18 tablets, nine sets of solutions, two tablets for each according to the previous optimal conditions," Han Jiaying paused, and added: "I have prepared a total of 20 zinc oxide substrates, which should be enough."

"No problem." Xu Qiu said confidently, 18 out of 20, that is to say, as long as the good product rate is 90%, it is not difficult for him.

Clean the glove box atmosphere, start spin coating, and wipe the slice with chloroform solvent simultaneously.

It took half an hour to obtain a total of 18 substrates with uniform film coating and zero mistakes.

Since these systems do not require annealing, Xu Qiu directly transferred them to the evaporation chamber and started vacuuming.

This new material, Xu Qiu didn't optimize it in Simulation Lab II, mainly because it was unnecessary, and the result was basically predictable, so there was no need to waste points.

Points are spent on the new non-fullerene acceptor developed by the senior sister, and the income will be higher.

After lunch, Xu Qiu continued to write the introduction to the graduation project.

Because his four works are mainly aimed at the traditional fullerene system of polymer donor materials, the non-fullerene review he published before cannot be directly translated as an introduction.

However, you can't translate your own, you can translate other people's.

Xu Qiu found several large reviews published by colleagues on AM, EES, and Chem. Rev., plus his own ACSEL review, a total of four, as reference materials.

In fact, based on Xu Qiu's current understanding of the field of organic photovoltaics, it is not impossible to write the introduction in his own words without referring to the literature, but it is more troublesome on the one hand, and there may be some omissions on the other.

The introduction itself is to gather the strengths of a hundred schools of thought. Now that you have decided to create a high-quality graduation thesis, you must take care of every detail.

In the evening, Han Jiaying got the test data of these devices.

Among the nine systems, the best system is the H13:IDT-ICIN system, with a maximum efficiency of 6.4%, surpassing the highest performance value of the previous IDT-ICIN system, but the improvement is not significant.

Although it is only a preliminary result, there is room for further improvement, such as reaching 7%, but it is still very difficult to expect to match the 10% efficiency of the "Nature·Materials" article.

This result, on the one hand, shows that the direction of this donor optimization is correct;

On the other hand, it also confirms Xu Qiu's previous speculation that the current combination of wide bandgap donor and narrow bandgap acceptor can only be icing on the cake for the optimization of donor materials, that is, a slight improvement on the original basis. The performance of the device has been greatly improved, mainly to tap the potential of the acceptor material.

In any case, as far as the current situation is concerned, another article can be published.

When you have your own system and have a first-mover lead, it is not difficult to fill in and publish articles in the second district or even the weaker district.

For example, for this job, at least one weak-level article such as JMCA, CM, etc., with better luck, there is also a chance to publish an AM sub-journal, AFM and other medium-level first-level articles.

However, after the first batch of these articles were published, other people learned about the "ICIN" unit, and the first-mover advantage was relatively weak. After all, other peers would follow suit.

If you can't keep leading the way, good articles will be divided up by others.

This is a test of luck and scientific research strength.

On Thursday, the senior sister was still doing synthesis in Zhangjiang.

Xu Qiu helped the school girl to apply the effective layer again, and also taught Wu Shengnan to process the TRPL data tested yesterday.

After arranging the two of them, Xu Qiu continued to write the introduction.

He worked until the evening, and finally finished the introduction. He wrote a total of 20 pages, and the total number of pages in the thesis reached 92 pages.

The introductory part has a total of six subsections, of which:

The first section is the introduction, which mainly tells why this graduation project is to be done.

Xu Qiu wrote three paragraphs, in a sequential manner, respectively describing "why to develop solar cells", "current status and existing problems in the field of solar cells", "development of organic solar cells is one of the ways to solve the problem ".

In the first paragraph, Xu Qiu directly translated the statement in his review:

"Humanity's demand for energy continues to increase, while traditional fossil energy sources such as coal, oil, and natural gas are increasingly depleted, and cause a lot of pollution to the environment. Therefore, finding various new energy sources, especially clean and renewable energy sources, is the most important task facing today's society. One of the problems. Among the many renewable energy sources, solar energy is generally considered to be an effective way to solve the global energy demand problem due to its non-polluting and unlimited use, but its utilization rate is very limited at present.”

In the second paragraph, Xu Qiu first described the current situation of the entire solar cell field: "The mainstream products of commercialized solar cells are traditional silicon-based solar cells, including monocrystalline silicon, polycrystalline silicon, and some thin-film silicon solar cells..."

Then the topic changed: "However, traditional silicon-based batteries also face many problems to be solved. For example, although monocrystalline silicon batteries have high photoelectric conversion efficiency, they require high purity of silicon, complex processes, large amount of materials, and production costs. High disadvantages..."

This paragraph mainly translates the big review of Chem. Rev., they are very detailed, after all, the article has more than 60 pages, and a review is worth the thickness of a master's thesis.

Finally, the third paragraph, following the second paragraph, introduces the main character of the graduation project "the field of organic solar cells", emphasizing the advantages of organic photovoltaics, including "light weight, low cost, strong selectivity, simple preparation, and good solution Processability and roll-to-roll printing onto large-area flexible substrates...".

In short, in a word, blowing is over.

This is also a common phenomenon in the scientific research circle. Practitioners are all bragging about how good their field is, but if you think about it carefully, if it is really that good, the entire industry will have been industrialized long ago, and it has been listed to make money. It is impossible to stay in the laboratory stage.

However, if you think about it from another angle, this kind of "boasting" is necessary.

If even the practitioners in the relevant field are not optimistic about their field, the entire industry will fall into a pessimistic atmosphere, and it is almost impossible to continue to develop.

Just like "the highest state of lying is to deceive yourself", for this cutting-edge field that tries to break through the bottleneck of human existing technology, there is a fog ahead, and the belief of practitioners is very important.

Only by persisting forward can we have a chance to dispel the fog.

The second section is "Basic Introduction of Organic Solar Cells", including "Photoelectric Conversion Mechanism of Organic Solar Cells", "Characterization of Organic Solar Cells", and "Basic Structure of Bulk Heterojunction Single-layer Photovoltaic Devices". This part mainly refers to Chem. Rev. that big review.

The number of references began to skyrocket, because when citing, you must specifically cite the original literature. That is to say, although some viewpoints are seen from the review, but these viewpoints themselves are cited by others, you must refer to them from the review. Find the original source and cite it.

In addition, in this part, Xu Qiu also stole four pictures from the review and pasted them directly in the graduation project, and indicated the source of the references in the captions of all the pictures.

The pictures are all the original pictures he found from the original text of the document. In fact, it is also possible to take a screenshot directly from the PDF, but the resolution will be reduced, and it may be discovered by Mr. Wei's sharp eyes.

The third section is "Polymer Donor Materials for Organic Solar Cells", including polymer donors synthesized from various types of donor structural units. Xu Qiu mainly refers to the review of that EES.

This part is relatively unfamiliar to Xu Qiu.

When I read this review before, it was when Xu Qiu just entered the industry. At that time, he was ignorant, and he went through it like a horse watching flowers, without gaining much.

Now that he has read it carefully again and transformed it into his graduation project, Xu Qiu has gained a lot, and has added a lot of ideas and inspirations for the design of the molecular structure of the donor.

The field of organic photovoltaics is an old field of more than 20 years. When Xu Qiu entered the industry, this field had already fully developed.

For example, the PCE10 he got, that is, PTB7-TH, is actually the product of seven generations of development.

For another example, the evolution process of D and A units in donor materials, from the early fluorene units and thiophene units, gradually enriched later.

These pre-artificial wheels can be flexibly applied in their own systems in the future.

The fourth section is "acceptor materials for organic solar cells", including traditional fullerene derivatives and emerging non-fullerene acceptors in recent years.

Fullerene derivatives, in addition to the PCBM series, there are actually many series, such as ICBA, Bis-PCBM, etc., but PC[60]BM and PC[70]BM are the most commonly used, Xu Qiu mainly refers to the AM article review.

As for the non-fullerene part, Xu Qiu simply took some content from his review, without describing it in detail, and briefly mentioned it. After all, his four works have nothing to do with non-fullerene.

The fifth section is "device performance optimization", which includes three parts, one is "effective layer morphology control", there are methods such as solvent additives, thermal annealing, solvent annealing, and the other is "interface engineering", which is mainly aimed at Modification of the transport layer, and finally "device structure optimization", including positive and negative device structures.

Section 6, "Proposal of the topic and research ideas", first echoes the introduction part of the first section, repeats why this graduation project is done, and then briefly describes the main content of each chapter paragraph by paragraph, that is, the main content of each chapter. The abstract of this article is abbreviated and put here.