A single solar cell just turned nearly 28.3% of the sunlight hitting it into electricity, a number so close to the physical ceiling for silicon that engineers are starting to talk about what comes after silicon altogether.

  • 28.29% power conversion efficiency — the new world record
  • 96.2% of silicon's theoretical efficiency limit now reached
  • 3 world records LONGi has broken in a single year
  • 28.04% → 28.13% → 28.29% — the company's record progression in 2026

How close to perfect can a silicon cell get

Chinese manufacturer LONGi announced the result for a hybrid interdigitated-back-contact (HIBC) solar cell, confirmed independently by Germany's Institute for Solar Energy Research Hamelin (ISFH), a leading photovoltaic testing lab. It beats the company's own previous record of 28.13%, set in May, and comes on the heels of a 28.04% result earlier in the year.

"Longi has broken the world records three times this year, pushing cell efficiency to 28.04%, 28.13% and 28.29%," the company said in its announcement, reported by PV Magazine. "The crystalline silicon solar cell efficiency is now approaching its technical ceiling, reaching 96.2% of the theoretical limit."

The crystalline silicon solar cell efficiency is now approaching its technical ceiling, reaching 96.2% of the theoretical limit.

The engineering behind the record

HIBC cells push efficiency higher by moving all of the electrical contacts to the back of the cell, so nothing on the front blocks incoming sunlight. LONGi's version layers passivated tunneling contacts with dielectric coatings and both n-type and p-type contacts on a high-resistivity silicon wafer.

The company added several refinements to squeeze out the latest gain: an indium tin oxide layer to improve how electricity moves across the cell, multilayer aluminum oxide and silicon nitride coatings to cut energy losses at the surface, and reduced phosphorus doping to limit unwanted diffusion into the wafer. A pulsed green laser is used to crystallize part of the cell without damaging its surface passivation — a manufacturing trick aimed at keeping the design practical to produce at scale, not just in a lab.

Why a lab record matters for your roof

Unlike many "world record" solar announcements that stay in the lab indefinitely, LONGi says this HIBC technology is already shipping. The company has reached mass production of 700-watt modules using related cell designs, sold under its EcoLife and Hi-MO 9 product lines, meaning gains like this one are on a path to actual rooftops and solar farms rather than just press releases.

Every fraction of a percentage point matters at scale: a solar farm built with cells a few points more efficient generates more electricity from the same footprint of panels, land and wiring, lowering the cost of the power it produces.

Crystalline silicon, the material in roughly 95% of solar panels made today, is now within striking distance of its hard physical limit near 29.4% efficiency. That is why LONGi, alongside rivals like Trinasolar and JA Solar, is already racing ahead with next-generation tandem cells that stack silicon with other materials like perovskite, aiming to blow past the silicon-only ceiling instead of just inching toward it.