The efficiency of crystalline silicon solar cells has exceeded 27% for the first time, and Longi's research results have been published in Nature

Recently, Longi Green Energy Technology Co., Ltd. (hereinafter referred to as "Longi"), as the first unit, published a research paper titled "Silicon heterojunction back contact solar cells by laser patterning" online in the journal Nature, reporting for the first time the research results of breaking through 27% of the photoelectric conversion efficiency of crystalline silicon cells through full laser patterning technology. This breakthrough marks the first time that the efficiency of crystalline silicon solar cells has exceeded 27%, setting a new milestone for photovoltaic technology and industry based on crystalline silicon materials.

It is understood that this study demonstrates the enormous potential of back contact (BC) batteries in achieving high efficiency and low cost. In order to achieve this high conversion efficiency, the Longi Central Research Institute team has conducted in-depth technical research in two key areas: silicon wafer and surface passivation contact technology. The team has developed a new type of dense heterojunction passivation contact, breaking through the industry's long-standing bottleneck of heterojunction preparation at 180-210 ℃, and achieving a process temperature of 240 ℃. At the same time, the R&D team has developed a full laser graphic process and low indium, silver free metallization scheme, which not only improves efficiency but also ensures the economic viability of BC battery technology, laying the foundation for low-cost and efficient BC battery production in the future.

In May of this year, Longi announced that its independently developed back contact crystalline silicon heterojunction solar cell (HBC) had a photovoltaic conversion efficiency of 27.30%, once again breaking the world record for single crystal silicon photovoltaic cell conversion efficiency. This is another breakthrough after Longi set the world record for HBC battery conversion efficiency of 27.09% in December 2023, and also represents Longi's confidence and strength in BC battery technology with high conversion efficiency and mass production process.

Over the past two decades, the manufacturing of crystalline silicon cells has undergone three major technological iterations. In the era of Al BSF (aluminum diffusion back surface field), the battery efficiency is less than 20%; In the PERC (passivated emitter back contact) era, the efficiency is increased to below 25%; The TOPCon (Tunnel Oxide Passivation Contact) technology upgrade that began last year has enabled the battery efficiency to exceed 25%. Looking ahead, over 26% of mass-produced battery technologies will be led by BC (Back Contact) technology. And the research achievements of Longi this time have pointed out the development direction of over 27% of ultra efficient battery technology for the industry: to promote efficiency improvement through the combination of heterojunction technology and BC structure infrastructure.

As a leading global solar technology company, LONGi adheres to a long-term development philosophy and is committed to continuously leading the technological changes in the industry through technological innovation. The publication of this research paper is the third article published by the Longi Institute of Central Research in the top academic journal Nature since 2024. The first article reported the world record for the efficiency of flexible silicon heterojunction cells based on different thicknesses, the second article reported the world record for the efficiency of perovskite/crystalline silicon stacked cells, and this article reported the world record for the efficiency of crystalline silicon cells based on BC structure.

This series of research results not only reflects Longi's profound accumulation in cutting-edge technology fields, but also further consolidates the company's global leading position in photovoltaic technology innovation. In the future, Longi will continue to cooperate with upstream and downstream industries to promote the practical application and landing of the new generation of BC technology, and help the photovoltaic industry move towards a more efficient and sustainable future.

Source: Yangtze River Delta Laser Alliance