Chinese solar manufacturer Trina Solar has achieved a record 24.13% total-area efficiency for a large-area (156 x 156sq mm) n-type mono-crystalline silicon (c-Si) Interdigitated Back Contact (IBC) solar cell at its State Key Laboratory (SKL) of PV Science and Technology (PVST).
The record-breaking n-type mono-crystalline silicon solar cell was fabricated on a large-sized phosphorous-doped Cz Silicon substrate with a low-cost industrial IBC process, featuring conventional tube doping technologies and fully screen-printed metallization.
The 156×156sq mm solar cell 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 243.3sq cm and was measured without any aperture.
The champion cell presents the following characteristics: an open-circuit voltage (Voc) of 702.7mV, a short-circuit current density (Jsc) of 42.1 mA/sqcm and a fill factor (FF) of 81.47%.
“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.
In February 2014, Trina Solar and the Australian National University (ANU) jointly announced a world record aperture efficiency of 24.37% for a laboratory-scale 4sq cm IBC solar cell, fabricated on a Float Zone (FZ) n-type substrate and using photolithography patterning.
In December 2014, Trina Solar announced a 22.94% total-area efficiency for an industrial version, large size (156x 156sq mm, 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%.
“We are very happy to announce today that our industrial large area IBC cell has reached almost the same level of performance as the small-area laboratory cell made three years ago with a photolithography process,” Dr. Verlinden said.
The new record of 24.13% total-area efficiency is just 0.24% absolute below the small-area laboratory cell record aperture-efficiency jointly established by the Company and 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.
“IBC solar cells are one of the most efficient silicon solar cells available today and are particularly suitable for applications for which the requirement of a high power density is more important than LCOE (Levelized Cost of Electricity). Our IBC cell program has always focused on the development of large-area cells and low-cost industrial processes,” said Dr. Verlinden.
“In an innovation-driven PV industry, Trina Solar is always focused on developing leading-edge PV technologies and products with improved cell efficiency and reduced system cost,” he added.