Solar Live Energy Outdoor Testing

For perovskite solar cells, however, it is not clear how to quantitatively correlate accelerated laboratory tests with outdoor operation: in particular, it is still not fully understood which stress factor, or which combination of factors, applied in the laboratory would accurately capture device degradation in the field.

Both academia and industry are in an active search for a single and quick ageing test to screen perovskite solar cell stability for accelerated material and device development.

For more accurate forecasts of outdoor lifetimes of perovskite solar cells, the model will need to be refined by including the dependence of the degradation rate on the dose and intensity of light, the level of relative humidity and other degradation factors (Fig. 1b ).

The stability of the devices is also improving: extrapolated operational lifetime of 50,000 hours has been reported for solar cells operating at 35 °C under laboratory conditions 1. To commercialize the technology, however, devices need to demonstrate decades-long operational lifetimes in the field where multiple stress factors are at play.

They show that long-term outdoor ageing can be predicted by modelling temperature-dependent degradation rates obtained by relatively short (that is, lasting less than a few hundred hours) light and heat stability tests performed in the laboratory.

Fig. 1: Prediction of outdoor device stability with modelled degradation rates inferred from laboratory stability tests.