Chapter 351: One step forward in efficiency, 13

A few days later, Xu Qiu got the test results from the simulation laboratory, and the device performance continued to make breakthroughs.
The best system is PBDB-TF: IDIC-4F, the photoelectric conversion efficiency can reach up to 13.52%.
Considering that the PBDB-TF donor material performs well in other non-fullerene systems, Xu Qiu decided to identify it as a benchmark donor material.
This faces a naming problem.
On the one hand, the name PBDB-TF is slightly longer; on the other hand, the original PBDB-T material is the result of the development of other research groups. Xu Qiu also has some selfish intentions and wants to fade this mark.
Finally, Xu Qiu imitated Xuemei to develop the FTAZ series from H1x to H4x, and named the three new PBDB-T derivatives, PBDB-TS, PBDB-TF, and PBDB-TSF, respectively J1, J2, and J3.
For Han Jiaying, now H is used and J is also used. In the future, there will be a new system that can be named Y series. I have to say that a three-character name is good.
Xu Qiu is not very interested in this method of naming it after his own name. Otherwise, he can simply call the ITIC series X1, which can be done, but it is not necessary.
Having said that, Xu Qiu does not plan to put too much energy into the donor at this stage.
Because he has very rich experimental data, and these experimental results show that for the "wide band gap donor: narrow band gap acceptor" organic photovoltaic system, the donor material is mainly the icing on the cake, and the device performance mainly depends on the acceptor. Material performance.
For example, IDIC-4F system, IDIC-4F combined with J2, the efficiency is 13.52%, but it is combined with H43, J1, J3, the efficiency is also not low, there are 11.92%, 12.27% and 12.98%, even if it is combined with light The combination of non-complementary narrow bandgap donor materials PCE10 and PCE11, the device efficiency both exceeded 10%.
The feeling for Xu Qiu is that if the acceptor material is very good, the requirements for the donor material are relatively low, as long as it is not too supportive, it is similar to the advantage called "the dog can win the tie." It is "any donor material will do." After all, the narrow band gap non-fullerene material is the main contributor to the photocurrent of this system.
In fact, the IDTBR system reported by Xu Zhenghong and others used a variety of standard donor materials to show good device performance. At that time, Xu Qiu had already guessed in this regard. Now a large amount of experimental data undoubtedly proves At the time his idea was correct.
Xu Qiu summarized his work on the J2: IDIC-4F system, with several highlights.
First, it is naturally high efficiency. Compared with the previous world record of 12.21%, which was stuck for three years, the device efficiency has increased by 1.31%, which is not small.
Second, similar to the previous IDIC system, the IDIC-4F system can also be used for thick films, such as 300 nanometer effective layer films, and the device efficiency can be greater than 10%.
Third, large-size devices based on this system, such as 1 square centimeter devices, can also achieve an efficiency of more than 10%.
The second and third points can be combined and then integrated with the inferences of the previous IDIC system, namely:
"Side chain changes→intermolecular steric hindrance decreases→acceptor molecule arrangement in the effective layer becomes tighter→electron mobility increases→thick film and large-size devices can be prepared, energy loss is reduced, and open circuit voltage is increased"
"Introduction of fluorine atoms → enhanced intramolecular interaction → deeper HOMO/LUMO energy level of the acceptor material, red shift of light absorption → increased short-circuit current, increased open circuit voltage"
If this is the case, it not only puts forward some new ideas, but more importantly solves a problem that has plagued the field of organic photovoltaics for many years, because although there have been systems that claim to be able to make large-size and thick films before, the efficiency is relatively low. No more than 10%.
High-efficiency examples are always more convincing than low-efficiency examples.
Moreover, for an area where the highest efficiency is recorded at about 12%, and most systems are below 10%, the efficiency breaking 10% is also of unique significance.
However, Xu Qiu was really entangled in the positioning of this job and what journal to submit.
Because in the academic circle, the top journals such as AM and the top journals of "Nature" and the top journals of the CNS level have a very large intermediate span, and there are basically no transitional journals.
It’s really bad whether the current job can be published in the
Nature
Dazi Magazine. It may be 50-50, depending on the editors assigned and the reviewers selected by the editors.
After all, Wei Xingsi is a newcomer in front of journals of the level of "Nature". Although he has mixed several "Nature" magazines through PY, they are all caught in the four-five-six-seven authors. There is nothing there. sense.
And if you vote for a top journal of this level, if the corresponding author doesn't have a halo, it's really a bit illusory.
If you voted for "Nature·Materials" and "Nature·Optics", when the reviewer comments come back and you are directly transferred to NC, it would be a bit embarrassing.
Although the NC is not bad, after all, a large part of the manuscripts that can be included in the NC are submitted to the "Nature" or "Nature" big magazines. As long as it is not random submissions, dare to submit to the CNS, "Nature" big magazines There are some things in the job, which is why some scholars think that NC is slightly higher than AM and JACS.
But if such a breakthrough work were to go to NC, Xu Qiu would not be reconciled after all.
If the device performance can break through to more than 14%, it will be more stable.
It's a pity that the results obtained in the simulation laboratory are getting closer and closer to the optimal conditions. Basically, what is measured is how much it is in reality. It is still difficult to increase 0.5%.
Xu Qiu estimated that the J2: IDIC-4F system in front of him is probably close to the ceiling of the performance of single-junction binary organic solar cell devices based on ITIC derivatives.
If you want to make a breakthrough in efficiency, you must either make major changes to the existing ADA non-fullerene system or make a double-junction tandem battery device.
However, these are two other stories, which have nothing to do with this job.
In the end, Xu Qiu thought about it and decided to aim for a new issue of the same level as "Nature·Materials" and "Nature·Optics".
New publications mean more opportunities. After all, there is a shortage of manuscripts, and the quality requirements for manuscripts will not be too strict.
Xu Qiu roughly has two goals, one is the latest major publication of "Nature" "Nature·Energy", and the other is the new publication of "Cell" Press "Joule", both journals are new publications in the energy category. , Highly related to his field.
Among them, it is worth mentioning the "Joule" periodical.
Joule, who has basically studied physics in middle school, knows that although he may not be as famous as Newton and Einstein, he is undoubtedly a person in the first echelon of science.
He was a physicist in Great Britain. In 1841, he discovered the conversion relationship between electrical energy and heat, which was later called "Joule's Law", that is, the heat generated by the current passing through a conductor is proportional to the square of the current and proportional to the resistance of the conductor. It is proportional to the power-on time.
Later, "Joule" was also designated as the international unit of energy and work. One joule of energy is equivalent to the work done by moving the point of force of 1 Newton in the direction of force by a distance of 1 meter.
"Cell" publishing house named "Joule" for the new publication. Obviously, it is not a small attempt. It may be planned to compete with "Nature" and "Science". Of course, it is basically impossible. After all, the age of CNS lies in There, the reputation has long accumulated, and even many ordinary people in China know the names of these two journals.
But in any case, under the strong promotion of "Cell" publishing house, "Joule" is still comparable to the influence of "Nature".
After determining the basic plan, Xu Qiu said to himself with emotion:
"My side J2 and IDIC-4F have been synthesized. In reality, they have just stayed at the stage of J1 and IDIC. It seems that we have to hurry up after the holiday is collected."
"Furthermore, there are quite a lot of things after the school starts, not only do the J2:IDIC-4F system, but also start to explore translucent, laminated devices, but also busy with the renovation of the Jiangwan laboratory and the relocation of the laboratory in the future. A few days ago, he agreed to go to Blue River for technical guidance."
"It really hurts to think about it."
During the summer vacation, Wei Xingsi did not harass Xu Qiu much. He just sent him a few AM and JMCA review papers, as well as some newly published documents. The two articles submitted before the holiday, AM and Angew have been submitted for review, but No comments came back yet,
When reviewing the manuscript, Xu Qiu looked at it at will. He is still relatively Buddhist, and he is generally less likely to reject people. He is not a tough reviewer.
AM’s article is a foreigner’s work. They are doing all-polymer organic solar cells. The system is similar to N2200. They made a ternary conjugated copolymer based on N2200 and introduced 5% of the N2200 molecule. The rigid backbone improves the device efficiency to more than 9%, breaking the world record for all-polymer organic solar cells. The previous world record was about 8.0%.
This foreigner’s work is quite rigorous, and the data is very informative. There are more than 20 pictures in the supporting information, all of which are ranked in Figure S22.
In the end, Xu Qiu made a few comments, which were regarded as "small changes."
According to Xu Qiu’s perception of the scientific research circles in the field of organic photovoltaics, the articles published by Asian researchers are generally more fluid. Except for the core highlights of the article, other places are basically more routine. Just look at the title and you basically know what they intend. What story to tell.
Researchers in Europe and the United States, relatively speaking, the workload of each job is not small. In many cases, there will be more "private goods", or opinions expressed in papers, so reading their articles will More troublesome.
The all-polymer organic photovoltaic system can now be called the name of the material, and there is only one kind of N2200, and the other materials are basically all on the street.
In fact, after Xu Qiu developed ITIC, he also had inspiration, thinking about making ITIC into a polymer form.
The structure of ITIC is ICIN-IDTT-ICIN, then introduce a single bromine atom to ICIN, and then directly carry out Stille coupling reaction with thiophene substituted by bistrimethyltin, and the structure is [ICIN-IDTT-ICIN-T] n polymer acceptor material.
The difficulty of synthesis is not too high, as long as the chlorine and fluorine atoms are replaced with bromine atoms, after all, I have already got ICIN-Cl and ICIN-F before.
With some effort, maybe you can post one or two AM grade articles.
However, Xu Qiu did not choose to explore this possibility on his own in the end, after all, the all-polymer field is a completely unfamiliar field to him.
Xu Qiu's scientific research philosophy is to focus on one direction to achieve the ultimate, interlaced like a mountain, too many cross-borders, it is easy to get involved.
Anyway, there are many researchers in the world. As Xu Qiu has developed a system with great potential like ITIC, others will naturally follow suit and supplement research in various subdivisions.
Maybe not every researcher has the ability to send CNS, but since you are in this profession and eat scientific research, you still have the ability to follow the trend and drink soup after the big guys.
Another JMCA review is the work of the domestic Xu Zhenghong research group.
They are still based on the IDTBR system, but the efficiency is not as high as other IDTBR systems, only 7.2%. This is probably the reason why they voted for JMCA.
Xu Qiu saw that there was no major problem with their work, 7.2% was not particularly low at this stage, so he did not stop, and offered a few comments, which is also considered a "small change."
However, Xu Qiu estimated that Xu Zhenghong and the others would not be able to produce any heavyweight results for a while.
After all, molecular structures like IDTBR have limited regulatory space:
First of all, the A unit is Rao Danning, unlike ICIN which has many active sites, and the molecular modification is not easy to change;
Next is the π unit, the BT unit, and the introduction of fluorine atoms has been published, and there is not much room for other optimizations;
The D unit again, IDT side chain regulation has also been done.
All they can do is to completely replace the D unit, that is, the skeleton structure of IDT, such as replacing it with IDTT or other structures, but this is very risky and may not be able to achieve benign results, and the probability of rushing to the street is high.
In addition to these two review papers, in the latest published literature, Xu Qiu saw that other researchers are also following suit, developing ADA-type non-fullerene receptor materials based on the ICIN unit.
There are two jobs, the corresponding authors are all domestic acquaintances, one is Gong Yuanjiang, the other is Bao Yuanyou.
Gong Yuanjiang did not say anything. He received a reminder from Teacher Wei during a meeting at Kainan University. Later, because of Mo Wenlin, he also got a lot of inside information.
Bao Yuanyou’s words surprised Xu Qiu slightly. Before UU Reading www.uukanshu.com, he was the worst speaker at the exchange conference. Now it seems that his academic sense is quite keen.
Both jobs are based on the IDT-ICIN system of Sister-in-law. After all, Xu Qiu's ITIC system has just been published on AM, and it is necessary to "let the bullet fly for a while".
The material efficiency of Gong Yuanjiang and Bao Yuanyou are not high, only 5.22% and 6.73%, which were published in "Big Molecules" and AFM respectively.
Seeing that Bao Yuanyou's work was published in "Big Molecules", Xu Qiu couldn't help feeling that the titles of academic journals are indeed somewhat formalized.
This ADA non-fullerene material is obviously a small molecule. As a result, this work can be published in the journal Macromolecules.
Of course, if you force the donor material to be a polymer or a macromolecule, it will make sense.
Two weeks of summer vacation passed in a flash, and in a blink of an eye it was the day to return to school.
Xu Qiu once again embarked on the green leather train to the magic capital.
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