IEC TR 63228:2019 summarises present perspectives on the performance evaluation of emerging PV technologies, specifically OPV, DSC and PSC devices. These devices present some challenges for accurate measurement under the existing IEC 60904 series of standards, which were developed in the context of silicon wafer solar cells. These challenges can be different for different devices, but in general they arise due to one or more of the following:
- instability in performance over time;
- unusual spectral responsivity;
- small device size; difficulty in measuring temperature;
- a transient response to external stimulus;
- optical interference effects; and
- a non-linear current response to irradiance. These challenges can lead to the cell output in laboratory testing being significantly different to the output that would be observed in a real application.
The primary focus of the report is measurement of the current-voltage (I‑V) relationship under illumination for the purpose of determining the device output power, or power conversion efficiency. Where appropriate, the report makes reference to the IEC 60904 series which describes the standard approach to measuring the performance of all PV devices. The report also references existing published standards that seek to accommodate OPV, DSC or PSC devices.