Search documents

Browse topics

Document details

Dry Plasma Texturing of Mono-Si for Silicon Heterojunction Solar Cells Application
M.L. Addonizio, L. Fusco, A. Antonaia, A. Spadoni
Texturing, Reflectance, Reactive Ion Etching
Wafer-Based Silicon Solar Cells and Materials Technology
Subtopic: Manufacturing and Processing
Event: 32nd European Photovoltaic Solar Energy Conference and Exhibition
Session: 2BV.7.33
935 - 939
ISBN: 3-936338-41-8
Paper DOI: 10.4229/EUPVSEC20162016-2BV.7.33
0,00 EUR
Document(s): paper


Dry and maskless texturing process of mono-crystalline silicon wafers using CF4/O2 plasma in a reactive ion etching (RIE) system has been studied for silicon heterojunction solar cells application. The main RIE process parameters have been changed and optimized in order to obtain a surface texture suitable to reduce the reflection of the silicon surface. Depending on gaseous mixture composition and process pressure, the etching mechanism can be modified from isotropic to anisotropic giving different shapes and sizes of surface features. At this purpose, effects induced by different plasma etching conditions on wafer surface morphology were systematically analysed in order to optimize the scattering properties. We verified that some typical texture parameters such as average Haze and RMS are not able to well explain reflection reduction. Differently, some specific texture functions such as angular distribution of scattered light and inclination angle distribution of the textured surface proved to be very effective in defining the most appropriate geometric surface parameters suitable to obtain large reflection reduction. In particular, with the aim of obtaining a textured surface with the lowest average reflectance in the wavelength range of interest, we have related the geometric parameters of the morphological features with the angular distribution of the scattered light obtained by ARS technique. Consequently, in this study we showed that, if shape and size of the characteristic surface features were appropriately modified by changing RIE process parameters, ARS curves very close to Lambertian behaviour can be obtained for etched silicon surface giving the highest reflection reduction.