Enhancing photon harvesting in organic solar cells with luminescent concentrators

The authors report on the application of luminescent concentrators on organic solar cells fabricated zinc-phthalocyanine and ${\mathrm{C}}_{60}$ . These solar cells have their main absorption in the wavelength range between 600 and $800\mathrm{nm}$ . Below $600\mathrm{nm}$ , the low absorption limits the quantum efficiency. Luminescence concentrators are used to overcome this limitation by spectrally shifting blue and green light towards the red and waveguiding it to the solar cell. With a second solar cell harvesting the red light transmitted through the concentrator, the photocurrent density is increased compared to a single solar cell of equal active area from about 8.5 up to $10\mathrm{mA}∕{\mathrm{cm}}^2$ .