Silicon heterojunction solar cells: Techno-economic assessment and opportunities

The ever-increasing electricity demand from renewables has stimulated growth in the photovoltaic (PV) industry.Yet, while grid parity has already been achieved in several countries, a continued decline in module prices coupled with further efficiency improvements at an annual growth rate of ~0.5%abs.are needed to sustain its market growth.Mainstream PV technologies are still based on crystalline silicon (c-Si) wafers with heavily doped regions and directly metallized contacts.However, these cause bandgap narrowing, Auger, and contact recombination losses.Passivating contact (PC) technologies can overcome these limitations by decoupling surface passivation and contact formation requirements.Amongst PC technologies, amorphous silicon based silicon heterojunction (SHJ) solar cells have established the worldrecord power conversion efficiency for single-junction c-Si PV.Due to their excellent performance and simple design, they are also the preferred bottom cell technology for perovskite/silicon tandems.Nevertheless, SHJ technology accounts for only ~2% of the present PV market share.In this review, we discuss the techno-economic challenges for large-volume SHJ manufacturing.In doing so, we highlight critical areas that need to be addressed for enabling terawatt-scale SHJ deployment.