Since 1986, the calibration laboratory at the Fraunhofer Institute for Solar Energy Systems ISE has been measuring solar cells, and since 1991, photovoltaic (PV) modules as well. Over the course of its forty-year history, it has calibrated the performance of thousands of solar cells and modules using a wide variety of technologies. To date, the “CalLab” has confirmed 152 record results. Sixty-six of these records were for PV modules—primarily silicon modules—while 86 referred to solar cells. The first record was set in 1992 by a mini silicon solar module with an efficiency of 16.4 percent, submitted by Deutsche Aerospace Aktiengesellschaft and featur-ing Bayer silicon wafers. The most recent record measured by CalLab con-firmed that a module from AZUR SPACE, temicon and Fraunhofer ISE, with an efficiency of 34.4 percent, is currently the world’s most efficient solar module.
“As a calibration lab, we have the privilege of closely following the efficiency development in photovoltaics,” says Martin Kaiser, head of CalLab PV Modules. While in the laboratory’s early days a small silicon PV module with an efficiency of 16.4 percent could set a record, today’s large-area silicon PV modules are already close to the physically possible limit. The most recent silicon record-breaking module measured at Fraunhofer ISE was submitted by Longi in 2025 and achieved an efficiency of 26.2 percent.
A total of 152 measurements taken by the CalLab PV Cells and CalLab PV Modules over the laboratory’s 40 years of calibration service confirmed new efficiency records. The figures are based on an analysis of the Solar Cell Efficiency Tables, versions 1 through 68, from 1992 to 2026. In an interactive graphic, interested parties can filter the individual values by cell type, area and technology.
To exceed the physical limit of silicon as a semiconductor, research groups worldwide are working to combine multiple subcells made of different semiconductor materials. As a result, CalLab has been calibrating an increasing number of tandem and multi-junction solar cells and modules in recent years. The world’s most efficient solar cell, with an efficiency of 47.6 per-cent, is a quadruple solar cell made of gallium-indium phosphide (GaInP), aluminum-gallium arsenide (AlGaAs), gallium-indium arsenide phosphide (GaInAsP) and gallium-indium arsenide (GaInAs). CalLab confirmed the world record in 2022.
“Our goal is to accompany every photovoltaic development with reliable measurements," explains Dr. Jochen Hohl-Ebinger, head of CalLab PV Cells at Fraunhofer ISE. “To this end, we are constantly refining our measurement technology—often in close collaboration with measurement equipment manufacturers—and working together with others on standardized measurement methods for new cell and module types within standards committees.” In particular, researchers have developed new measurement technologies and methods in recent years for measuring perovskite-silicon tandem solar cells and modules. CalLab PV Modules, for example, uses a new multispectral solar simulator.
“Independent calibration laboratories that are respected by all industry stakeholders world-wide are essential for the photovoltaic industry,” says Prof. Dr. Andreas Bett, director of Fraunhofer ISE. “Impartial and transparently traceable performance measurements enable fair competition. Ultimately, all stakeholders benefit from this.”
