Investigation on Post Cleanings on Modified Surface Using Laser Texturing

The surface of crystalline silicon (c-Si) solar cells can affect their performance as the surface can alter both electrical and optical properties. The c-Si texturing is carried out to increase the absorption; therefore, the optical properties will be enhanced. The anisotropic alkaline etchants are commonly used to form pyramids on the surface of monocrystalline Si wafers. However, this method is not usable for multi-crystalline silicon (mc-Si) because of its grains with random crystallographic orientations. The laser texturing, as an alternative method for texturing mc-Si wafers, is getting attention among texturing techniques. In this study, post-texture cleaning is investigated since it is a vital step after the laser texturing. This approach includes preparing the cleaning solution and performing the cleaning on the laser processed mc-Si wafers' surface. The different solution parameters, such as cleaning duration, temperature, and concentration, are justified by performing a series of experiments. To determine the effectiveness of the process, the weighted reflection and Scanning Electron Microscopy (SEM) images of the samples are considered. The SEM images show the evolution of the surface morphology versus cleaning duration, temperature, and concentration. Moreover, the measurements indicate that the samples’ weighted reflection can change dramatically by changing the cleaning solution parameters.