  In general, perovskite solar cells (PSC) with a sensitized or thin film
architecture absorb light from a single illumination. This paper reported a PSC
architecture with a semitransparent Au/ITO counter electrode, which allows
light to pass it partially. When the device was illuminated simultaneously from
both the FTO and Au/ITO sides, the PSC has achieved an overall power conversion
efficiency (PCE) as high as 20.1% under high light intensity (1.4 sun), which
is much higher than that of the single-irradiation system.
