Cell Processing

The development of new ways of increasing the production throughput for passivated emitter and rear cells (PERCs), as the major solar cell technology in the global market, is an area of great interest to the PV community. This paper presents approaches for significantly increasing the throughput of PERC production processes. The main focus is on the tube furnace processes for the emitter formation and oxidation, with the introduction of the High Temperature Stack Oxidation (HiTSOx) approach. Additional approaches that are currently under investigation at Fraunhofer ISE for increasing the throughput for wet-chemical, printing and laser processes will also be briefly outlined.

The holy grail of every solar cell producer is the creation of a lowcost interdigitated back-contact (IBC) solar cell with an efficiency greater than 25%, a goal that can be found in almost every roadmap presentation. In this paper it will be shown that we are not far away from achieving this target, since IBC devices, with different process complexities, are already in production at several companies.

This paper will accordingly outline the recent activities at CEA-INES concerning the development and understanding of the integration of such shingle cells.

In this paper, an even greater reduction in wafer thickness, down to 130μm, is evaluated, and the critical steps in terms of breakage rates in cell and module production processes are reviewed. Finally, the mechanical stability and reliability of these thin HJT cells in glass–backsheet and glass–glass module types are addressed.

This paper provides a short overview of historical developments, presents the main approaches in mass production today, discusses potential process simplifications, and briefly touches upon a key topic for the future, namely reducing the silver (Ag) consumption per cell.

This paper presents preliminary results of SERIS’ biPolyTM cell: the bifacial application of polysiliconbased passivating contact stacks with front and rear screen-printed and fired metallization.

This work reports the latest results obtained at Jolywood for full-area (251.99cm2) n-type bifacial passivating-contact solar cells using a cost-effective process with industrially-feasible boron diffusion, phosphorus ion implantation and low-pressure chemical vapour deposition (LPCVD) with in situ oxidation.

This paper reviews the key technology improvements which have enabled a continuous 0.5%abs/year increase in efficiency of industrial PERC and PERC+ cells.

Silicon heterojunction (SHJ) solar cell technology is an attractive technology for large-scale production of solar cells with a high conversion efficiency beyond 24%. One key element of SHJ solar cells, contrasting with today’s widespread passivated emitter and rear contact (PERC) cell technology, is the use of transparent conductive oxide (TCO), which poses challenges in performance and costs but also presents opportunities. This paper discusses these aspects and shows the potential for improving cell efficiency at reduced cost by using new TCOs deposited by direct current (DC) sputtering.

In this paper the situation of solar cell production in China is summarized, and an attempt is made to answer the question of whether passivated contacts could replace PERC technology, which will eventually reach its efficiency limit in the future.