In the production process of perovskite solar cells, ITO thin film deposition is a key step that can improve the photoelectric conversion rate of perovskite solar cells. Among them, vacuum evaporation deposition technology can more conveniently prepare high-purity and high-quality ITO thin films. It is a core technology in the deposition process. Millennial Solar relies on our rich testing experience and superb testing technology to produce the Spectrophotometer. This equipment can help solar cell manufacturers correct the absorbance changes in the ITO film of perovskite solar cells more conveniently and scientifically, thereby making it better to ensure the quality of solar cells.

Learn more about vacuum evaporation deposition

Vacuum evaporation coating, referred to as vacuum evaporation for short, refers to heating the raw materials to be formed into a thin film in the evaporation container in a vacuum chamber, causing the atoms or molecules to decompose and overflow from the surface to form a vapor flow, which is incident on the surface of the perovskite solar cell. , a method of condensing to form solid films such as ITO films. Since vacuum evaporation technology is mainly produced by heating evaporation materials, it is also called thermal evaporation method or thermal evaporation.

The process of depositing ITO thin films using vacuum evaporation

To use vacuum evaporation coating technology to deposit ITO films, the heating and evaporation process must first be carried out, that is, the phase change process of converting the condensed phase into the gas phase. Since each evaporating substance will have different saturated vapor pressures at different temperatures, the components will change when the compound is evaporated, and some of the components will enter the evaporation space in the form of gas or vapor.

Secondly, the transport process of vaporized atoms or molecules between the evaporation source and the surface of the solar cell is carried out, that is, the flight process of these particles in the ambient atmosphere. The number of collisions with residual gas molecules in the vacuum chamber during flight depends on the mean free path of the evaporated atoms and the distance from the evaporation source to the substrate.

Schematic diagram of vacuum evaporation deposition of ITO thin film

Finally, the deposition process of evaporated atoms or molecules on the surface of the perovskite solar cell is carried out, that is, vapor condensation, nucleation, nucleation growth, and formation of a continuous thin film. Since the temperature of the solar cell surface is much lower than the temperature of the evaporation source, the sediment molecules will directly undergo a transformation process from the gas phase to the solid phase when they are on the cell surface.

Elaborate on the many advantages of vacuum evaporation

● The coating method is simple: Vacuum evaporation only requires heating the material to be deposited to a high enough temperature. The equipment structure is relatively simple and easy to operate.

● High film purity and density: Compared with other deposition technologies, vacuum evaporation deposition technology is carried out under high vacuum conditions, which can effectively reduce the impact of impurity gases and dust particles on the deposition process. At the same time, due to the high kinetic energy of the deposited atoms, a dense and uniform structure can be formed on the surface of the battery sheet.

● The thickness can be controlled more accurately: Vacuum evaporation can control the deposition rate and thickness by adjusting parameters such as heating power, time, distance, etc. It can also use the Stylus Profiler produced by Millennial Solar to measure and feedback parameters such as the thickness of the deposited ITO film in real time, thereby feeding accurate data to solar cell manufacturers to help them produce efficiently!

● Fast film formation rate and high efficiency: Vacuum evaporation can use resistance, electron beam, laser and other methods to heat materials to quickly reach saturated vapor pressure and generate a large number of gaseous particles, so that the deposition process can be completed in a short time , and can deposit multiple different materials simultaneously or separately.

Millennial Spectrophotometer

E-mail: market@millennialsolar.cn

Millennial Spectrophotometer adopts a unique dual-beam optical design that can perfectly correct the absorbance changes of different ITO films, allowing for stable sample measurement.

● Adopt dual light source and dual detector design, ultra-large wavelength range 190-2800nm

●Double grating optical structure effectively reduces stray light

● The diameter of the integrating sphere can reach 100mm. It will not turn yellow after long-term use and has stable optical performance.

● Signal processing technology can minimize errors caused by detector switching

In the deposition process of perovskite solar cells, vacuum evaporation deposition technology plays an important role. It can achieve the effects that other deposition technologies can achieve through tedious processes through a very convenient deposition method.

Therefore, it can be applied to the industrialized preparation process of solar cells. The Spectrophotometer produced by Millennial Solar can start sample scanning with one click by setting the detailed information of the sample to be tested, thereby meeting the industrial testing needs of battery manufacturers!