Offline and Inline thin film and reflectance properties and camera based solutions for wafer based solar cells.

Helios / SiCAM wafer solar solutions

Several production steps are needed to produce a solar cell. The most important steps in the process chain are the texturization of the bare wafers for reducing the wafer reflectance, the doping to generate the pn-junction and the SiN-coating to increase the anti-reflective effect as well as the passivation of the wafer surface. All these process steps have a significant influence on the cell efficiency. Therefore nxt offers several inline and offline testers for process and quality control to ensure the stability and homogeneity of the process parameters in the different process steps. At the end this guarantees the best cell performance with the highest possible cell efficiency.

Principle of Measurement

The Helios and SiCAM product line uses our well known spectrometer and camera technology. This technology is proven since 20 years in different industrial areas. Optimized optical setups for the particular tasks are used to measure high accurate reflectance spectra and camera images. Based on these data, nxt uses high sophisticated mathematical algorithms and physical models to calculate the relevant parameters like layer thicknesses, refractive indices, absolute reflectance values and other parameters very accurate and stable.



High end, low cost or fast offline measurement for wafer solar solutions



Inline measurement of SiN coating thickness and refractive index on solar wafers direct after the coating process



Inline gap distance control of Silicon melt and heat shields in crystal pullers