Chapter 17 I want to see the teacher’s true strength!
This was the first time Ke Zhan encountered such a situation, and he couldn't help but want to dampen the other party's enthusiasm. He was so arrogant on the first day of class, what would happen in the future?
Besides, he really wanted to see Luo Yao's strength.
Who knows, maybe the other party can add glory to your future professional title evaluation.
However, class was in session and so many people were watching. If Ke Zhan were to give Luo Yao a test on his own now, he would inevitably be known as a petty-minded person among the students. He decided to find an opportunity to test Luo Yao.
"Okay, since Luo Yao has already learned all the lessons for this semester, why not listen again and see if your understanding is consistent with what we are going to explain?"
Luo Yao thought it made sense, so he continued to sit and wait for Ke Zhan to start his lecture.
Ke Zhan composed himself and immediately got to the point.
He was going to continue teaching basic theories today, but when he thought of Luo Yao's words just now, he temporarily changed the content of the lecture and switched to explaining exercises.
This was a tough situation for the other students, as they were still confused about even the basic theories. When they saw the questions Ke Zhan posed on the blackboard, their eyes suddenly went dark.
"Okay, let's take a look at this problem. Suppose there is a p-n junction solar cell chip."
"The electron mobility of the p-type semiconductor is μ_p, the electron diffusion coefficient is D_p, and the boron ( B) doping concentration is N_A. The electron mobility of the n-type semiconductor is μ_n, the electron diffusion coefficient is D_n, and the phosphorus (P) doping concentration is N_D."
"The surface reflectivity of the solar cell is R, the incident light intensity of the sun is I_0, and the incident angle is θ."
"Come, let's calculate the short-circuit current (I_sc) of this solar cell."
After Ke Zhan finished speaking, everyone in the classroom fell silent.
"Fuck, this question is so vicious, are you trying to kill me?" Wang Ye lived in Bengbu, and he didn't recognize half of the things on the blackboard.
What else is there to learn?
He now really regrets that he entered this department based on his good physics grades.
"So what? Don't you all know?" Ke Zhan held the chalk in his hand and glanced at Luo Yao.
Didn't you say you've already taught yourself?
Why is there no response?
Ke Zhan felt a little disappointed.
It seems that Luo Yao is more good at talking than at actual strength.
The first prizes in three subjects in the national competition are probably because the test questions this year were too simple.
We really need to take good care of people like this in the future, otherwise they will be beaten by society when they enter the society.
Of course Luo Yao didn't move, because he wanted to see how the other person's way of solving the problem differed from his own.
For Luo Yao, solving problems is the process he enjoys the most. If he can learn new problem-solving methods, then he will gain something.
"Come on, let's start solving the problem."
"First, we need to understand what short-circuit current is. Short-circuit current is the current of a solar cell when there is a short-circuited external load resistance at both ends of the battery. That is—"
"Isc=q·μp·NA·μp·ND·TW·I0·sin(θ)"
"Teacher, there is a problem."
Before Ke Zhan started to speak, Luo Yao raised his hand and started to speak.
What the hell?
He actually saw the problem?
Just as the other students were about to fall asleep, Luo Yao's voice dispelled their sleepiness.
Everyone looked at the blackboard and didn't see any problems.
"What's the problem?" Ke Zhan was stunned. He frowned and looked at Luo Yao, motioning him to stand up and speak.
"Teacher, the assumption in the question is a PN junction solar cell chip."
"When considering the short-circuit current (Isc) of a PN-type solar cell, we have to consider two key factors: the electron doping concentration of the n-type semiconductor (N D) and the electron doping concentration of the p-type semiconductor (NA)."
"These two differences in doping concentration lead to concentration gradients of electrons and holes, which in turn affect the current flow."
"In a PN junction, when an n-type semiconductor and a p-type semiconductor come into contact, electrons flow from the n-type semiconductor to the p-type semiconductor, while holes flow from the p-type semiconductor to the n-type semiconductor, resulting in a redistribution of charge."
"So when you do the calculations, it should be like this."
After Luo Yao expressed his thoughts, he walked up to the podium without any hesitation, took out a pen and added a few strokes to the formula written by Ke Zhan.
Isc=q·(μn·ND－μp·NA)·TW·I0·sin(θ)
"μ_n·N_D and μ_p·N_A represent the contributions of electrons in the n-type semiconductor and holes in the p-type semiconductor, respectively. The difference between the two makes up the current of the entire solar cell."
"This current is generated by a built-in electric field, the magnitude and direction of which are determined by the difference in doping concentration."
"So this is the correct way to calculate short-circuit current."
As Luo Yao spoke, Ke Zhan was verifying it, and soon he knew that Luo Yao was right.
He didn't expect that Luo Yao would notice this little mistake.
To save face, Ke Zhan could only say, "This is just a small mistake on my part . Teacher, I recently published a paper, so I was very busy and didn't get enough rest."
"paper?"
"What is your research area?"
"Design and Implementation of Microchip Power Circuit Driven by Solar Photovoltaic Cell Modules." This is Ke Zhan's masterpiece. Ke Zhan has been preparing for the title of associate professor this year. To be evaluated as an associate professor, he has to publish papers, so he is indeed busy.
After he finished speaking, he did not forget to ask the students to find semiconductor journals to study.
In order to dispel the embarrassment caused by Luo Yao correcting him just now, Ke Zhan basically talked about the process of writing this paper.
Luo Yao returned to his seat and after listening, he felt that Ke Zhan's level was mediocre.
After the get out of class, Ke Zhan quickly took his book and left.
After Wang Ye saw Luo Yao leave, he sighed and said, "You said you were too disrespectful to correct him just now. What if he secretly tries to make things difficult for you?"
Luo Yao frowned: "No, even if Mr. Ke's level is not high, he would not do this."
"Shh!" Wu Tianming hurriedly stopped Luo Yao from talking any further. After leading the two out of the classroom, he said, "Are you two crazy? Discussing this in the classroom, what if someone hears you and tells on you?"
"What's the point of doing this?" Luo Yao looked puzzled.
Wu Tianming said quietly, "Of course it's to pass the exam."
"University bully, the final exam score is divided into exam score and regular score. The failure rate of our major is around 60%. Can you guess how many people do extra work just to get the full regular score?"
"If you continue like this, what if your regular points are deducted?"
"What percentage of the total score does the regular score account for?" Luo Yao thought about it and decided to ask the most crucial question first.
“30%.”
"That's not bad. Even if all the points are deducted I can still pass." Luo Yao said nonchalantly.
Wu Tianming and Wang Ye looked at each other, knowing that this was something only a top student would say.
"By the way, where is the school library?" Luo Yao suddenly became interested.
"It's in a building outside."
"Do you want to read a book?"
"I went to see Professor Ke's paper. I wanted to see his true abilities."
