Cheng, Y.Y.; Fückel, B.; MacQueen, R.W.; Khoury, T.; Clady, R.G.C.R.; Schulze, T.F.; Ekins-Daukes, N.J.; Crossley, M.J.; Stannowski, B.; Lips, K.; Schmidt, T.W.: Improving the light-harvesting of amorphous silicon solar cells with photochemical upconversion. Energy & Environmental Science 5 (2012), p. 6953-6959
10.1039/c2ee21136j
Open Access Version (externer Anbieter)
Abstract:
Single-threshold solar cells are fundamentally limited by their ability to harvest only those photons above a certain energy. Harvesting below-threshold photons and re-radiating this energy at a shorter wavelength would thus boost the efficiency of such devices. We report an increase in light harvesting efficiency of a hydrogenated amorphous silicon (a-Si:H) thin-film solar cell due to a rear upconvertor based on sensitized triplet–triplet-annihilation in organic molecules. Low energy light in the range 600–750 nm is converted to 550–600 nm light due to the incoherent photochemical process. A peak efficiency enhancement of (1.0 0.2)% at 720 nm is measured under irradiation equivalent to (48 3) suns (AM1.5). We discuss the pathways to be explored in adapting photochemical UC for application in various single threshold devices.