In the full range of sunlight luminescence (300~2500nm), its energy in the visible light range (400~760nm) accounts for 43%, the energy in the ultraviolet region (<400nm) accounts for 5%, and the energy in the near infrared region (>760nm), the energy accounted for 52% of the total energy. At present, Millennial spectrophotometer can fully meet the needs of collecting reflecta and transmittance data of ito thin films in the full band of 190-2800nm, and is widely used in the photovoltaic industry.

TCO Film

Low resistivity, high light transmittance, and low-temperature growth are the basic requirements for TCO thin films for SHJ cells. The high infrared reflectivity of traditional TCO films limits the effective utilization of long-wavelength sunlight energy by solar cells using it as a transparent electrode.

The resistivity of the TCO film is inversely proportional to the carrier concentration and mobility. By reducing the carrier concentration, the absorption of free carriers can be reduced, thereby improving the light transmittance, but reducing the carrier concentration will lead to a decrease in the resistivity of the film. rise to affect conductivity.If the carrier mobility is increased while reducing the carrier concentration, on the one hand, due to the reduced carrier concentration and reduced absorption, high transmittance from visible light to near-infrared range can be achieved, which is conducive to the improvement of solar cell efficiency.

Improve TCO Carrier Mobility

There are many ways to improve the carrier mobility of TCO thin films, including selecting the appropriate deposition method, annealing heat treatment after deposition, controlling the crystal structure, controlling the impurity concentration, selecting the doping method, introducing hydrogen, and selecting the appropriate dopant etc. ITO thin films are widely used in SHJ cells due to their advantages of low resistivity, high visible light transmittance and low temperature deposition (≤200°C). However, the traditional ITO carrier mobility is relatively low, which is determined by the scattering mechanism such as ionized impurity scattering. Doping the In₂O₃ system with the following dopants can obtain In₂O₃-based TCO films with high mobility:

■ Hydrogen-doped In₂O₃ (IO:H)

■ Tungsten-doped In₂O₃ (IWO)

Although these two In₂O₃-based TCO films have superior properties to ITO films, the deposition temperature is generally higher than 250°C, and further optimization is required if they are to be applied to SHJ batteries.

Millennial Spectrophotometer

E-mail: market@millennialsolar.cn

Millennial spectrophotometer Can be used to measure material transmittance, reflectance and absorbance.

Millennial spectrophotometer The unique double-beam optical design can perfectly correct the absorbance changes of different sample matrices, so that the samples can be measured stably. It has the advantages of wide testing range, high precision and good stability. And it supports the measurement of solar transmittance in a wide range of wavelength regions from the ultraviolet region to the near infrared region, providing strong support for the efficiency analysis of solar cells.

The characteristics of low resistivity and high light transmittance of TCO film can greatly improve the efficiency of solar cells. Millennial Spectrophotometer supports the measurement of reflectance and transmittance of ito films in the ultraviolet to near-infrared region, helping you open a new future for optical detection!