I Have a Research Support System

Xu Qiu first glanced at Mo Wenlin's substrate after spin-coating and wiping through the glass of the glove box.

It was found that except for two pieces that were slightly imperfect and a few grainy bumps appeared on the effective layer film, the other six pieces were very well done. The blue-green film was coated very evenly, and the yield rate can be considered to be 100%.

In the laboratory, as long as the coated film does not have obvious delamination, or large-area defects such as radial structures, occasionally some granular protrusions, that is, "point defects", will not affect the final small-area test. It is enough to avoid the defective parts during the test.

"The film coating technology has made great progress." Xu Qiu praised, and then skillfully put his hand into the evaporation glove box.

Mo Wenlin said with a smile: "It may be that the IEICO system is easier to paint. I used to do the PDI system, and the coated film often had problems, especially when using chlorobenzene solvents, it is easy to appear radial."

"Well, the PDI system is really difficult," Xu Qiuying said, and then shifted the topic to the business: "The key to the preparation of translucent devices is the preparation of translucent electrodes. I chose thin-layer metal electrodes. method of preparation."

"Hmm..." Mo Wenlin thought for a moment, and said, "Is that similar to normal vapor deposition, except that the thickness of the metal electrodes is thinner?"

"That's right, the specific operation will be more troublesome than usual vapor deposition, and you need to use gold and silver at the same time." Xu Qiu explained, while putting the substrate on the sample stage, paused, and added: " After that, I will ask you to help me make some devices repeatedly.”

"Well, no problem." Mo Wenlin agreed, then stood by and watched Xu Qiu's operation seriously.

Xu Qiu gave Mo Wenlin a preventive shot first. The "some devices" he mentioned just now are not five batches or ten batches of duplicate devices in the previous binary system, but dozens of batches of devices.

Because when preparing translucent devices with thin-layer electrodes with different thicknesses from 10 nanometers to 20 nanometers, each electrode thickness needs to be prepared separately, unlike the binary system, even if the systems are different, they can be evaporated simultaneously in one batch.

It can’t be said that I evaporate 10 nanometers first, then take it out for testing, put it back, and then evaporate 2 nanometers, so it becomes 12 nanometers.

This is obviously not possible. If the device preparation process is not carried out continuously, there will be additional variables, which will reduce the accuracy of the experimental results.

Assuming that each condition only prepares 5 batches of devices according to the minimum repeatability standard, the six conditions will add up to at least 30 batches of evaporation.

Fortunately, in this case, the limit number of device batches that can be prepared by evaporation per day can also be increased from the original two batches a day to three batches a day, because the operation before evaporation can be completed in multiple batches at the same time.

For example, a system can be spin-coated 18 pieces at one time, and then divided into three times, and six pieces are evaporated and tested each time.

Moreover, the accuracy of the data obtained in this way will be higher. After all, it is an effective layer obtained by simultaneous spin coating.

The disadvantage is that it needs to be busy from morning to night, and it is tiring.

Of course, when it comes to specific operations, the work can be split up.

For example, Mo Wenlin was responsible for the more difficult spin coating work, and then the evaporation work was handed over to Xu Xinjie, an undergraduate who had just joined the group, or borrowed Yu Ya and Deng Hu from Wu Feifei.

Yin Houlang can't be counted on for the time being, he basically doesn't appear in Caiyi 216 now, and often runs to the Zhangjiang campus to learn organic synthesis skills from Wu Shengnan.

"This time I plan to vapor-deposit 1 nanometer of gold and 9 nanometers of silver to obtain a thin-layer electrode with a total thickness of 10 nanometers." Xu Qiu continued to introduce.

"Why do you need to evaporate two layers?" Mo Wenlin asked curiously.

"Gold is relatively dense, and compared with silver, it is not easy to penetrate into the molybdenum trioxide and the effective layer below, and can form a dense continuous gold film..." Xu Qiu explained his previous thoughts.

"That's it." Mo Wenlin nodded as if realizing something, and said, "Gold is equivalent to an electrode buffer layer."

"Well, more or less." Xu Qiu responded, and then found the reagent bags and reagent bottles containing gold and silver evaporation targets, as well as two tungsten crate containers that had been ultrasonically cleaned with isopropanol, and prepared charge.

The evaporation cabin has four beam source furnaces and two current heating devices. Generally, one beam source furnace is used to evaporate the transmission layer, such as molybdenum trioxide, and another current heating device is used to evaporate metal electrodes, such as gold, Silver, aluminum.

Today two electric current heating units and a beam source furnace unit are used.

The tungsten basket is made of high-purity tungsten. There is a basket structure in the middle, which can place the target. The length of the two sides extending about 3-4 cm is used to be fixed.

The melting point of tungsten is very high. When the current passes through the tungsten basket, it will generate high temperature. The high temperature can melt other metals, but the tungsten basket itself will not be melted.

Xu Qiu began to load the target.

The first is silver, because silver is relatively cheap, so the laboratory bought a lot of it at one time.

The silver target is simply packed in a plastic vial which is similar in size and shape to the licorice tablet bottle. Each one has a similar size, about 0.5 cm in length and 0.3 cm in diameter. The cut marks that are sunken in should be made by making the silver into filaments first, and then cutting it.

Xu Qiu directly threw two silver particles into the tungsten basket. Usually, about 5 silver particles are used to deposit 100 nanometers of silver, but now 9 nanometers are deposited, and two particles are definitely enough.

In theory, it should be enough to put a silver grain.

But in matters such as evaporation, I would rather use more than less, because once less, these devices will be directly useless.

After all, the evaporation experiment has non-fixed loss, and the degree of loss varies according to the evaporation rate. Generally, the slower the evaporation rate, the more target materials are lost.

When preparing thin-layer electrodes, in order to make the metal electrodes continuous and uniform, the evaporation rate must be reduced.

Fix the tungsten basket containing the silver target on the current heating device, and Xu Qiu continued to install the gold target.

The gold target is packed in a transparent plastic bag. The original factory may have an opaque plastic bag outside the transparent plastic bag for safety reasons.

Gold is relatively expensive. The purity used in the laboratory is at the 99.99% level, and the price is more expensive than the ten thousand pure gold on the market.

Of course, the price also fluctuates, and the price is different every time you buy it from a company that specializes in target materials.

Occasionally, Xu Qiu would receive sales news from the target company: "Recently, the price of gold has been on the rise again. Dear, do you want to store some gold targets in the laboratory?"

This batch of gold targets is also in the shape of a cylinder with a diameter of about 0.3 centimeters, but the length is relatively long, about 0.8 centimeters. It is also a relatively standard cylinder with no shear marks at both ends and is slippery.

Xu Qiu took out a gold target, cut it into three pieces with clean scissors, put one piece into the tungsten fistula, and put the other two pieces back into the plastic bag.

Usually, about 2 silver particles are used to deposit gold with a thickness of 100 nanometers. Now, one-third of the particles should be enough for 1 nanometer deposition.

The price of gold is relatively expensive, if you can save it, you should save it.

Xu Qiu used the same operation method to fix the tungsten basket on the current heating device, took out the molybdenum trioxide beam source furnace, and replaced it with some new molybdenum trioxide. After finishing, he said: "Mo Wenlin, turn on the mechanical pump."

After finishing speaking, Xu Qiu put the door of the evaporation chamber back to its original position, and firmly grasped the two handles on the door to withstand the door, keeping the inside of the evaporation chamber sealed and not in contact with the glove box outside.

"Okay." Mo Wenlin pressed the start button of the mechanical pump, and there was a roar.

After three seconds, Xu Qiu pulled the two handles of the vapor deposition cabin out, but when he found that he couldn't pull them apart, he let go of his hands and slowly exited the glove box.

It is said that this method of closing the hatch was first proposed by Wu Feifei.

This is a non-mainstream method of closing the hatch. The principle used is to make the air pressure in the vapor deposition chamber lower than that outside the vapor deposition chamber, so that the vapor deposition chamber door will not fall.

As long as you keep the hatch sealed for the first few seconds, there will be no pressure difference after which the hatch will not fall.

It is when the air pressure is balanced when the inflation is completed, the hatch will fall onto the track, and there will be a crash sound. When Xu Qiu first joined the research group, she was once teased by her senior because of this matter.

The main purpose of this operation is to save time.

If it is a conventional door closing operation, it is necessary to wind the two large screw structures on the evaporation hatch door dozens of times to fix the hatch door, that is, to lock the door, and when the hatch door is opened, the door needs to be locked again. To open the lock, if there is no one outside to help, you need to go in and out of the glove box to operate the console by yourself. These trivial steps will take about five minutes.

It takes five minutes to evaporate a batch of devices, and 500 minutes to evaporate 100 batches of devices.

During the experimental operation, as long as it does not affect the safety of the experiment and the safety of the instrument, the operation that can save time is of great significance.

Evaporation can only be carried out when the vacuum reaches the level of ten minus five Pascals, and it takes a while.

So, Xu Qiu and Mo Wenlin returned to the office. Han Jiaying didn't come to the laboratory this afternoon because of business, and their communication became more.

Normally, when the junior girl sees that the two communicate too much, even if it is related to scientific research, she will listen in on the sidelines. If she encounters a field she knows, she will squeeze Xu Qiu under the banner of "helping girlfriends" Walk.

Regarding this, Xu Qiu was a little helpless, but he did not reject the behavior of the school girl, so he let it go.

After the two sat down at the desk, Mo Wenlin took the initiative to ask: "Can this translucent device also be used in the ternary system?"

"It's not necessary..." Xu Qiu said subconsciously, but he changed his mind and overturned his just judgment: "Actually, it can also be used in the ternary system, such as developing translucent devices of different colors, which is indeed a ternary system." One of the advantages of the system over the binary system is that it can control the ratio of three different color materials, just like the palette of pigments, so as to obtain translucent battery devices of various colors without adding dyes... ..."

"I have an idea," Xu Qiu snapped his fingers suddenly, and said, "We can prepare a batch of devices of different colors based on a ternary blend system, and then use these devices to create a painting, such as " How about "Scream" or something? Isn't this a very eye-catching gimmick."

Mo Wenlin paused for a while before saying quietly: "Xu Qiu, your brain is really big..."

PS: Happy New Years Eve everyone~