Today PV market is dominated by multicrystalline-Si (mc-Si) and monocrystalline-Si (c-Si) technologies with a market share above 90%. These technologies take advantage from scale economy and utilization of mature manufacturing processes with standardized materials. To compete in such a tough market more and more PV modules manufacturers are targeting the development of modules that are able to reduce energy cost, leveraging on efficiency, module durability and more energy generation at high operating temperature.
The hydrogenated amorphous Si / crystalline Si heterojunction technology (Si - HJT) is very attracting since it exhibits several fundamental characteristics that render PV modules more efficient, allowing them to generate more energy for longer time. These characteristics have a remarkable effect on the reduction of the levelized cost of energy (LCOE), which is the relevant characteristic of a PV installation.
Compared with mainstream technologies, Si - HJT cells are intrinsically bifacial and can be fabricated at low temperatures (<200°C), which enable the use of thinner silicon wafers, thus further reducing costs.
Si – HJT technology roadmap relies on the development of efficient selective contacts as well as nanotechnology solutions for improving transparent contacts performances and light trapping in the absorber material, in particular for enabling a significant reduction of crystalline silicon thickness in the solar cell. This work will report the most recent research and industrial developments for the Si - HJT technology, describing the technology roadmap as well as the expected advantages with respect to conventional technologies.