In the deposition process of solar cells, photovoltaic cell manufacturers often take into account the various factors that affect the performance of solar cells with ITO films in order to effectively deal with the performance problems encountered by solar cells during the deposition process.

Thereby improving the photoelectric conversion rate of solar cells.The Spectrophotometer produced by "Millennial Solar" can use new data processing software to scientifically, intelligently and efficiently detect the light transmittance of ITO films after the deposition process.This enables solar cell manufacturers to quickly adjust and optimize the performance of solar cells based on real-time generated data.

The structure of ITO film

The structure of ITO film is mainly determined by its crystal phase, grain size and grain boundary defects. Generally speaking, the simpler the crystal phase of an ITO film, the larger the crystal grains, and the smaller the grain boundary defects, the better its conductivity and transparency will be. Therefore, in order to improve the structural quality of ITO films, some methods can be used to control crystal phase growth and inhibit grain refinement, such as changing deposition temperature, air pressure, doping elements, etc.

Thickness of ITO film

The thickness of the ITO film has a complex impact on the performance of solar cells, and is also the factor that most directly affects the performance of solar cells. On the one hand, the thicker the ITO film, the better its electrical conductivity will be, which can reduce series resistance and ohmic losses. On the other hand, the greater the thickness of the ITO film, the worse its transparency, which will increase light reflection and absorption losses. In order to balance the impact of the thickness of the ITO film on the performance of solar cells, it is necessary to select an appropriate thickness range according to different types of solar cells.

Schematic diagram of surface thickness of ITO film

For crystalline silicon solar cells, due to their high light absorption coefficient and low carrier lifetime, a thicker ITO film needs to be selected to increase its light transmittance and reduce its surface recombination. For amorphous silicon or organic solar cells, due to their low light absorption coefficient and high carrier lifetime, a thicker ITO film needs to be selected to improve its conductivity and reduce its series resistance. Stylus Profiler produced by "Millennial Solar" can accurately measure a series of important parameters such as film stress and thickness of deposited films. Solar cell manufacturers can make timely adjustments and optimizations to solar cell production based on the differences between measurement results and preset standards, so that they meet industrial standards.

Morphology of ITO film

The morphology of ITO films is mainly determined by its surface roughness and formation mode. Generally speaking, the smaller the surface roughness of ITO film, the better its transparency, thereby effectively reducing light scattering and reflection losses. However, an ITO film that is too smooth will also reduce the contact area and adhesion between the film and other layers, affecting the stability and life of the solar cell. In addition, the formation mode of the ITO film will also affect the interface characteristics and carrier transfer efficiency between the film and other layers. Therefore, in order to optimize the morphological characteristics of ITO films, some methods can be used to adjust parameters such as deposition rate, oxygen flow, and substrate temperature.

Surface treatment of ITO film

ITO films are often affected by factors such as oxidation, hydrolysis, and adsorption during the preparation or use process, resulting in some impurities or defects on the surface of the film. These surface defects will reduce the conductivity and transparency of the ITO film, increase the interface energy level and energy level difference between the film and other layers, and affect the photoelectric conversion rate of the solar cell. In order to improve the surface quality of ITO films, some cleaning, annealing, redox, plasma treatment and other methods can be used.

Schematic diagram of the surface structure of ITO film

In order to further test the quality of the improved ITO film, you can first use the Stylus Profiler produced by "Millennial Solar" to accurately measure the roughness, waviness, film stress, and thickness of the ITO film, and generate real-time data and images to give clear and objective images and data presentation. After the measurement is completed, continue to use the Millennial Four-Point Probe Tester to conduct a fully automatic multi-point scan of the solar cell after the deposition of the thin film to obtain accurate sheet resistance and resistivity data, so that the solar cell manufacturer can directly understand the completion of the deposition process. Whether the solar cells meet industrial standards so that scientific and objective adjustments can be made!

Millennial Stylus Profiler

E-mail: market@millennialsolar.cn

Millennial Stylus Profiler is an advanced micro-nano measuring instrument that uses excellent instrument system structure and optimized measurement and data processing software to measure surface roughness, waviness, surface 2D/3D shape, and film stress. This enables reliable, efficient, and simple sample testing and completes perfect control from research and development to quality control.

●Equipped with 5 million pixel high-resolution color camera

●Step height repeatability 1nm

●Ultra-high straightness guide rail, reflecting the micro-morphology of the sample

●Sub-angstrom resolution, up to 0.01 angstrom in 13μm range

●High and low noise ratio and low linear error

Millennial Four-Point Probe Tester

E-mail: market@millennialsolar.cn

Millennial Four-Point Probe Tester can quickly and automatically scan samples up to 230mm to obtain sheet resistance/resistivity distribution information at different locations of the sample. It can be widely used in photovoltaics, semiconductors, alloys, ceramics and many other fields.

●Ultra-high measurement range, measuring 0.1MΩ~100MΩ sheet resistance

● High-precision measurement, dynamic repetition rate can reach 0.2%

● Fully automatic multi-point scanning, multiple preset schemes can also be customized and adjusted

● Rapid material characterization and automatic calculation of correction factors

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 for stable sample measurements.

●Adopt dual light source and dual detector design

●Super large wavelength range 190-2800mm

●Double grating optical structure effectively reduces stray light

●Integrating sphere diameter can reach 100mm

●No yellowing after long-term use, stable optical properties

●Can minimize errors caused by detector switching

Since ITO films have an important impact on the performance of solar cells, solar cell manufacturers need to optimize the structure, thickness and morphology of ITO films according to different application requirements and process conditions, to achieve the photoelectric conversion rate required for industrialization. Spectrophotometer produced by "Millennial Solar" can be used to measure the conductivity and light transmittance of ITO films, and based on scientific test results, it helps battery manufacturers to effectively improve the performance of solar cells, thereby producing high-quality solar cells!