Detection of shot noise in perovskite solar cells and related devices

Hybrid organic-inorganic perovskite solar cells are one of the most promising emerging technologies with the capability to compete with established silicon devices. The effective commercial rollout of perovskite-based devices, however, requires a fundamental understanding of the material’s electrical transport properties. We have performed current noise spectroscopy on a series of methylammonium lead triiodide perovskite solar cells. Under illumination, the noise power spectrum exhibits two main components: a 1/f^a flicker noise and a frequency-independent white noise. Our main finding is that this white noise is associated with photo-generated shot noise. The extracted Fano factor (0.6 < F < 1) indicates that the observed shot noise is full scale and that the photo-generated carriers have no significant barriers to escape the device. We have performed a similar series of measurements on amorphous silicon solar cells as well as super yellow PPV polymer-based LEDs, the results of which will also be presented.