Perovskite Now Has an I-V Testing Standard — Field EL Reading of Tandem Modules Still Lacks a Common Reference

ⓘ This article is currently published in Chinese. An English version is being prepared — read the Chinese original.

In late 2026 China's market regulator released the first national standard for measuring the current-voltage (I-V) characteristics of perovskite cells and modules, taking effect in 2027, while the country's first two-terminal silicon-perovskite tandem outdoor demonstration project broke ground on the Qinghai plateau. Together these two events mark tandem modules stepping out of the lab and onto real power plants. But a standardized way to measure I-V does not solve the other half of the problem: how to read the EL image of a tandem module in the field. Tandem modules stack a perovskite top cell on a silicon bottom cell, so their emission spectra, current matching and defect signatures differ from ordinary crystalline-silicon panels, and the reference frame field inspectors have relied on for years no longer fits. This article explains why field EL reading of tandem modules is harder, what changes when inspection moves from the production line to an outdoor plateau site under drone or portable EL survey, where the EL standardization gap still sits behind the new I-V standard, and what plant owners and demonstration projects can do right now — resolution, current injection, spectral matching and AI-assisted interpretation — so that tandem-specific defects are actually caught rather than hidden inside an unfamiliar image.