Introduction

The energy transition from traditional fossil energies to renewable energies is one of the greatest societal challenges of the present generation. Among the different types of renewable energies, photovoltaics (PV) is considered as one of the most stable and matured technologies. The mainstream of the current PV technology is based on crystalline silicon (c-Si) solar cells. The research and development in this field is mainly driven by the improvement of the energy conversion efficiency and the reduction of module production cost.

The commercialization of high-efficiency PV modules based on next-generation c-Si solar cells will depend on their cost competitiveness to the existing conventional c-Si technology. Despite their higher efficiency as compared to the standard Aluminum Back Surface Field (Al-BSF) technology, a large-scale industrial changeover to these new concepts has not yet been initiated due to several reasons:

(i) Wafer manufacturers need to make a huge change in their production lines from p-type to high quality n-type mono wafer;
(ii) Cell and module manufacturers also have to significantly upgrade their production line with new equipment or invest in new production lines;
(iii) The simple process and thus the low production cost of the Al-BSF currently used in industry is yet hard to compete with by new technologies.

High-efficiency solar modules by SunPower (USA) and Panasonic (Japan) in “interdigitated back contact (IBC)” and “silicon heterojunction (SHJ)” configurations, respectively, are already commercially available.