Large area solar panels see 24% record efficiency

May 05, 2017 // By Nick Flaherty
Trina Solar's IBC monocrystalline panel
Chinese solar panel maker Trina Solar has set a new record of 24.13% total-area efficiency for a large-area Interdigitated Back Contact (IBC) solar cell.

The n-type mono-crystalline silicon (c-Si)n-type mono-crystalline silicon solar cell was fabricated on a 156 x 156mm2 phosphorous-doped Cz silicon substrate with a low-cost industrial IBC process featuring conventional tube doping technologies and fully screen-printed metallization. The cell, developed by Trina’s State Key Laboratory (SKL) of PV Science and Technology (PVST) reached a total-area efficiency of 24.13% as independently measured by the Japan Electrical Safety & Environment Technology Laboratories (JET).

The IBC solar cell has a total measured area of 243.3cm2 and was measured without any aperture with an open-circuit voltage Voc of 702.7mV, a short-circuit current density Jsc of 42.1 mA/cm2 and a fill factor FF of 81.47%.

Trina has been pushing the efficiency of these large cells to stay ahed of perovskite-based cells that are increasing in efficiency. In February 2014, it jointly announced a world record aperture efficiency of 24.37% for a laboratory-scale 4cm2 IBC solar cell, fabricated on a Float Zone (FZ) n-type substrate and using photolithography patterning with the Australian National University (ANU). In December 2014, Trina Solar announced a 22.94% total-area efficiency for an industrial version, large size (156x 156mm2, 6" substrate), IBC solar cell. In April 2016, Trina Solar announced an improved industrial low-cost IBC solar cell with a total-area efficiency of 23.5%.

The new record of 24.13% total-area efficiency is just 0.24% absolute below the small-area laboratory cell record aperture-efficiency with ANU. Total-area efficiencies are always lower than aperture-efficiencies, due to efficiency losses related to the edges of the cells and electrical contact areas.

"We are very delighted to announce the latest achievement from our research team at the SKL PVST. Over the last few years, our R&D team has managed to continuously improve the efficiency of our n-type IBC solar cells, pushing the limits and surpassing our previous records, and approaching very closely to the performance of our best small-area laboratory cell developed in collaboration with ANU three years ago." said Dr. Pierre Verlinden, Vice-President and Chief Scientist of Trina Solar, which last month