Chapter 25: On the importance of research fields

　　 "Senior elder sister is better, and the highest can be 4.5%." Xu Qiu said.
　　 "My 4.5% is the highest value," Chen Wanqing said: "I have made dozens of batches of devices, only two times have reached that high, most of the time it is still between 4% and 4.4%."
　　 "If the elder sister had not figured out the conditions, and the installation and equipment were set up and connected, I would not be so smooth." Xu Qiu said.
　　 "Alright, don't be humble," Chen Wanqing said: "Continue to test, it will take a long time to test."
　　 In fact, before the results of the experiment came out, she was still a little nervous, after all, this was the data she needed.
　　 When conducting experiments, there will always be various accidents. Some can be avoided by experience, while others cannot.
　　 For example: the cleaned substrate is missing; when the effective layer is about to be spin-coated, it is found that the oxygen content of the glove box is >500ppm; the fuse is blown when half of the evaporation is completed, etc.
　　 Especially for multi-stage experiments such as device preparation, an accident in any one of the steps may cause the entire experiment to fail.
　　 The most important thing is that the operator of the experiment is not herself. She is not sure whether Xu Qiu can handle the various unexpected situations encountered during the experiment.
　　 "Now it seems that the younger brother is still reliable, I can add more burden to him in the future." Chen Wanqing thought happily.
　　 Relatively speaking, Xu Qiu is relatively calm.
　　 He felt that he was operating in full compliance with the specifications. If this fails, then he...
　　 There is no way.
Man proposes, God disposes.
　　 He can only do it again, trying to find the reason.
　　 The operating reasons were ruled out, which may be caused by medicines, equipment, and accidents.
　　…………
　　 Xu Qiu continued to scan and test the device repeatedly under light conditions, and save the data for each test.
　　The photoelectric conversion efficiency is constantly fluctuating:
　　 4.30%, 4.36%, 4.33%, 4.28%, 4.30%, 4.26%, 4.24%, 4.25%, 4.22%...
　　 Looking at this changing trend, Xu Qiu asked:
　　 "Why is the conversion efficiency fluctuating and decreasing?"
　　 "Because the PC[60]BM in the effective layer is unstable," Chen Wanqing explained: "Under long-term light, it will produce dimers, destroy the original blend film morphology, and cause the degradation of photoelectric conversion efficiency."
　　 "Then this material is unstable to light, why is it still used to make solar cells? Isn't this a pit?" Xu Qiu puzzled.
　　 "Well...From the perspective of industrial applications, it is indeed a huge problem," Chen Wanqing said:
　　" But if this material is perfect, then it is not necessary to study it in the laboratory, and it can be used directly for industrial applications.
　　 It is precisely because of its imperfection that it is necessary to spend energy to study it, but the premise is that this field has application prospects in the future.
　　 The country puts out a lot of billions for scientific research every year, and distributes it to a number of fields, which is to cast a net in the world. In the end, if one or two big fish can be netted, it will make a profit.
　　Of course, there is also a competition mechanism in this. The better the development prospect, the more resources you can get;
　　 In areas where there has been little achievement, there has been no capital injection until the later period, and scientific research resources are not available, and the entire industry has slowly cooled down.
　　 is like the dye-sensitized battery that was still hot a few years ago. Few people are doing it now, and it may only appear in textbooks in a few years.
　　 Similarly, if our current field has not achieved any breakthrough results in a few years or more than a decade, it will slowly die out.
　　 As you said, the problem of poor stability can only be ranked second at present. The primary problem is that the photoelectric conversion efficiency is too low. In addition, there are cost issues, large area preparation issues, and so on. "
　　 "Oh -" Xu Qiu deliberately dragged the long tone: "Understood."
　　 Chen Wanqing was amused by him: "Tell me, you know what."
　　 "In the scientific research circle, you must either be the big boss and lead the trend, or be the big boss's younger brother and keep up with the trend, or you will be eliminated." Xu Qiu said.
"Um... I always feel that you are talking about something wrong," Chen Wanqing tilted her head to ponder for a while, and said: "But for us students, choosing a research direction is really important. I have heard many tragic cases before. "
　　"A student from the Department of Agriculture, the experimental corn planted in the field was stolen by a passerby and cooked and eaten. As a result, he worked for nothing for a year;
　　 Ph.D. in the Department of Physics, I chose a very unpopular spectroscopy study. As a result, the instrument broke as soon as I arrived in the research group, and it has not been repaired after two years;
　　Ph.D. in the School of Pharmacy, researched anti-cancer drugs with his supervisor, and discovered that the supervisor's data was falsified near graduation;
　　 Archaeology student, studied a certain cultural relic for more than a year, and finally concluded that it was a modern imitation. "
　　 "It's really miserable." Xu Qiu smiled.
　　 Chen Wanqing spread her hands and said:
　　 "Okay, I'm going to slip away, brother, come on."
　　 Then she got up and went back to the desk.
　　 The remaining work is to repeat the test, there is no difficulty in operation, but it takes a lot of time.
　　 There are a total of 21 substrates, each with 6 batteries, and it takes about 2 minutes to test one battery.
　　 Fortunately, there is a stool next to the glove box, you can sit down and do experiments.
　　……
　　 Time passed by every minute.
　　 Around nine o'clock, UU Reading www.uukánshu.com Tian Qing left.
　　 At ten o'clock, Teacher Wei took a look at the laboratory, said hello to everyone, and confessed that he closed the doors and windows when he left and left.
　　 Then Feifei Wu and Duan Yun also left.
　　 There are only two people left in the laboratory, Xu Qiu and senior sister.
　　 "I will accompany you to finish the test."
"it is good."
　　 The two were busy until half past eleven.
　　 The campus at this time is not as hot as it was during the day, and there are fewer people.
　　 After walking side by side for a while, they separated. The undergraduate and graduate dormitories are not in the same area.
　　The conditions of the dormitory for graduate students are much better. There are three or four-room ensuite rooms with bathrooms. One person can live in a room for doctors and two people can live in a room for masters. The campus card is inserted 24 hours and there is hot water for bathing.
　　…………
　　 Xu Qiu returned to the dormitory and found that Ren Bin was lying on the bed and playing with his mobile phone. Tao Yan was missing.
　　 "Xu Qiu, it's so late today." Ren Bin heard the door opening, struck a carp directly, and sat up.
　　 "Yes, I haven't finished the experiment, I can't leave. Where is Tao Yan, are you going out to be happy again?"
　　 "I don't know, he didn't see him back after carrying a schoolbag in the afternoon."
　　 "Well, let him go, I'm going to take a bath." Xu Qiu said as he sorted out the toiletries.
　　 "Now that the bathrooms are closed, you are not going to wash cold water in the corridor, right."
　　 "Go to take a shower, it's summer, it's not a big problem."
　　 corridor bathroom.
　　 "Huh."
　　 Xu Qiu stood under the shower head, turning the water flow to the maximum.
　　 The jet of water hit the body, and there was a slight pain.
　　 He took a closer look at the top of his head, and it turned out that the nozzle was broken.