Industrially feasible all-purpose metal-wrap-through concentrator solar cells

Abstract

The authors combine a silicon-based metal-wrap-through architecture with a unit cell designed for the purpose of operating under concentrated irradiance, called AP-MWT solar cell. On the illuminated side, the negative polarity is electrically separated by using an emitter window surrounding the perimeter of each unit cell. The final solar cell device consists of an arbitrary number of unit cells with sizes ranging from 1 × 2.25 cm2 up to 14 × 13.5 cm2. The Czochralski based bulk material as well as the manufacturing approach use state-of-the-art industrially feasible technologies alone. Results show a plateau between concentration factors from 5 to 12 reaching efficiencies above 20.0%. An average efficiency of 19.8±0.15%, for over 150 AP-MWT solar cells measured at a concentration factor of 10, is reported. Details on the interconnection and module design will be discussed in another contribution to this conference

A review of concentrator silicon solar cells

“…Fellmeth et al made the metal wrap through (MWT) cell for concentration using industrial crystalline silicon solar cell manufacturing process, the efficiency was larger than 20% under 5-12 suns [78]. The MWT cell was a combination of bifacial contact cell and back contact cell, the grids were made on the front surface of the cell, but the bus-bars were made on the back surface and connected to grids through the roles in the cell to decrease the shading losses [57,[78][79][80], the structure of the MWT cell drew by Lohmüller et al is shown in Fig. 11 …”

GaInP/AlGaAs metal‐wrap‐through tandem concentrator solar cells

“…The challenge of high currents and metal shading in silicon PV has led to the development of metal‐wrap‐though (MWT) technologies in which the emitter and base contacts are both realised on the rear side of the device. Insulated holes are filled with metal to transport the electric current from the front to the back side where both contacts are isolated and collected in an interdigitated metal grid . This technology has led to Si solar cells with an efficiency up to 21.0% (AM1.5 g) .…”