Chapter 28: Active overtime

　　 After preparing the three sets of solutions, Xu Qiu said goodbye to her senior sister and left the laboratory.
　　 will enter the one-month exam month starting next week.
　　 He only took 14 credits this semester, a total of 6 courses, the examination pressure is not great.
　　 But it is still necessary to review carefully to prevent overturning. After all, not being able to drop a subject is a rigid indicator of the research.
　　 Therefore, Xu Qiu decided to catch up with the experimental progress this week and at least verify his previous ideas.
　　…………
　　 On Tuesday, Xu Qiu had lunch and arrived at the laboratory at one o’clock.
　　 In the corridor, he deliberately imitated Teacher Wei's footsteps and walked "DaDaDa".
　　 opened the door of 216, Xu Qiu and Chen Wanqing looked at each other.
　　 "Ah, it's Xu Qiu," Chen Wanqing took a long breath and said, "I thought it was Teacher Wei who came. You did it on purpose."
　　 "Of course not. My shoes have a hard bottom, so the voice is louder." Xu Qiu naturally refused to admit it, walking behind her and said:
　　 "Senior sister, what are you doing, sneaking."
　　 "As for chasing drama, I just thought it was Teacher Wei, so I closed the website." Chen Wanqing said.
　　 "Isn't it just a little bit now? It's not working time. Even if it is discovered by Teacher Wei, it will be fine." Xu Qiu said.
　　 "I was arrested twice by him for chasing dramas during working hours. Although he didn't say anything, I was a little bit embarrassed, so it is better not to be discovered by him when paddling." Chen Wanqing said:
　　 "By the way, you can give me your student ID, and I will help you apply for the access control of the laboratory."
　　 "1230713XXXX." Xu Qiu said.
　　 "Well, I will send an email to the teacher in charge of access control in the department." Chen Wanqing said.
　　 "Okay, Senior Sister, then I will do the experiment." Xu Qiu said.
　　 "So positive," Chen Wanqing said: "Okay, you go, pay attention to safety."
　　 She originally planned to teach Xu Qiu to use the UV-Vis spectrophotometer to test the light absorption performance of the effective layer film, and then let him help her measure a few samples.
　　 Seeing his full of energy now, Chen Wanqing decided to test it himself or talk about it in a few days.
　　 She was very curious about what new experimental ideas Xu Qiu had, but he didn't want to say it, and it was hard for him to keep asking.
　　Thinking that when I first entered the laboratory, I was always repeating the work of others, proficient in various instruments in the laboratory, and had no new ideas at all.
　　 It wasn't until later that the reading volume of literature increased, that I figured out the routines in this field.
　　 So I chose a kind of donor and two kinds of acceptors to blend, and found that the performance of the device was improved from 4.5% to 4.8%, and then I did characterization and tried to tell a story.
　　The materials are all purchased, and I mix them by myself. In fact, there is not much innovation, it is in the water article.
　　 Why don't you post an article, you can't finish your career. The group's request is for four SCI second districts. She doesn't know if this article can be published in the second district, maybe only a third district.
　　 She thought of her junior, who was so talented in scientific research and so hardworking.
　　 People who are better than me work harder than me, how can I indulge in TV dramas.
　　 After pouring herself a large bowl of chicken soup, Chen Wanqing closed the website and continued to write her article.
　　…………
　　 Xu Qiu started the experiment after taking protective measures.
　　 He first turned on the ultrasonic cleaner, cleaned the substrate, and then went into the glove box to check the dissolution of the solution prepared yesterday.
　　 After inspection, all three bottles dissolve very well.
　　 Among them, the chloroform solution is special, because its boiling point is 61.7 degrees Celsius, and the set temperature of the rotary heating table is 60 degrees Celsius, so Xu Qiu put it on the lid of a petri dish first, and then placed it on the heating table.
　　 There is still some remaining zinc oxide prepolymer solution. Xu Qiu observed that its color changed from the colorless and transparent at the time of initial preparation to the color similar to egg white, slightly yellowish.
　　 He asked the senior sister the reason for this color change before.
　　 Chen Wanqing told him that she didn't know the specific reason, only experience.
　　 According to her experience, the performance of the prepared battery device like this slightly yellowed prepolymer solution will be better than the newly prepared solution, but the difference will not be too great.
　　 However, if it is left for a long time, the solution will eventually turn into a dark yellow color similar to urine, and it cannot be used.
　　 Applied scientific research like materials is usually result-oriented.
That is to say, the researchers first obtain a good result through continuous trial and error, and then reverse the analysis, analyze the reason for the good result, propose a guess, and then determine the next trial and error direction, and then repeat Promote the progress of the research field.
　　 So many times, the reason is unknown.
　　……
　　 Xu Qiu washed the substrates, spin-coated zinc oxide prepolymer solution, and annealed to obtain 24 ITO/zinc oxide substrates.
　　 I looked at the time, it was past three o'clock.
　　 He thought about it, and decided to work overtime today to finish this batch of devices and test them out.
　　 Continue to spin coating the effective layer, a total of 15 experimental conditions, each must have at least one piece.
　　 The normal spin coating operation is relatively simple. Xu Qiu did not make any mistakes and obtained a film that evenly covers the entire substrate.
The 　　 spraying method is more difficult, and what he used to redeem 500 points was a one-time teaching, and the existing points are not enough to redeem again.
　　 Without the real-time guidance of the system, Xu Qiu can only use the memory in his mind to explore the conditions on his own.
　　 For the first time~EbookFREE.me~ He put the pipette gun perpendicular to the substrate and sprayed directly like normal spin coating operation, and finally formed a big hole in the center of the film.
　　 For the second time, he sprayed the pipette gun obliquely. As a result, his hands shook during the operation, and finally there was obvious delamination on the film.
　　 After two experiments failed, Xu Qiu decided to use glass instead of ITO substrate to try the hand feel.
The 　　 spraying method saves more solution. 1 ml of solution can be sprayed more than 40 times, while the spin coating can only be about 15 times, so it is not afraid of waste.
　　He used the remaining solution from last time, and after more than ten practice exercises, he finally came up with the operating tips:
　　 First cut the pipette tip from the middle, 20 microliters of solution, and press the start button of the homogenizer;
　　 Then, aim at the edge of the substrate at a place where the gun tip is about 5 cm away from the substrate, and squeeze out all the solution at an angle of about 45 degrees;
　　 During the whole process, the amplitude of hand shaking should not be too large, and the speed of solution extrusion must be fast.
　　Count the number of remaining substrates: a total of 24 substrates, 17 were used, and 7 were left.
　　 Xu Qiu thought for a moment and decided to change the conditions of experimental group B to:
　　Chloroform (10 mg/ml, 1:1), chlorobenzene (16 mg/ml, 1:1), dichlorobenzene (20 mg/ml, 1:1); rotation speed 1000, 1200, 1500; spray method.
　　In this way, just 6 more substrates can be used, and 1 is left.
　　 The next experiment did not give any surprises. Xu Qiu annealed the spin-coated substrate with solvent, thermal annealing, and wipe.
　　 then transfer to another glove box, after installation, start the evaporation device, start vacuuming.
　　 Finally, I returned to the desk to rest and waited for 5:30.