Measuring a solar cell's IV curve is a five-minute operation, reporting a trustworthy efficiency is a discipline. The efficiency number depends on light calibration, temperature and scan conditions, and small slips in each add up to large differences between labs.
Calibrate the solar simulator with a certified reference cell, matched in spectral response class to the device under test, and set 1 sun (100 mW/cm²) at the test plane. Verify uniformity across the full sample area, a non-uniform beam biases every device larger than the uniform zone.
Device parameters drift with temperature, particularly open-circuit voltage. Hold the device at a stated temperature (25 °C is standard) with an active stage, and report it. A device left to warm under the beam loses voltage while you watch.
Define scan direction, speed and voltage steps, and pre-condition identically. Hysteresis-prone devices, perovskites above all, demand forward and reverse scans with the difference reported. A single fast scan of a hysteretic device is not a measurement, it is a lottery ticket.
Extract Voc, Jsc, fill factor and efficiency with a fixed, documented procedure. Cross-check Jsc by integrating the external quantum efficiency against the reference spectrum, disagreement between simulator-Jsc and EQE-Jsc flags a calibration problem.
State simulator class, reference cell, temperature, scan parameters, device area and masking. An efficiency number without these details is not reproducible in the next room, let alone the next lab.
Perfectlight's solar test platforms integrate source, stage and acquisition for standardized IV workflows; see light source solutions.
