full harvEst of solar radiatioN using a quantum-dot-in-perovskite absorber and LIGHT managemENt structures

ended

Europe has set the energy transition to renewable sources as one of its priority policies to minimise the effects of climate change. Photovoltaic energy is called to play a major role in the world’s electricity production in the mid-term. The present market-dominant technology, crystalline silicon, has reached its practical efficiency record of 26% and the energy cost of this technology seems to be stagnating now. For these reasons, research on new ways of increasing the conversion efficiency of solar cells is still extensive. Among the proposed novel concepts for high-efficiency solar cells, the intermediate band solar cell (IBSC) has received great attention by the scientific community. In conventional single-gap solar cells, photons with energy lower than the bandgap of the absorber material are wasted. The IBSC concept allows harvesting below-bandgap photons without voltage loss, which increases the limiting efficiency from 33% to 50%. So far, IBSCs have been realized with epitaxially-grown quantum dot (QD) superlattices of III-V semiconductors. However, no pronounced efficiency enhancement has been yet reported, since this technological approach is unable to produce nanostructured materials with the properties required theoretically. In particular, epitaxial QDs exhibit low absorbance, leading to low photocurrent, and weak quantum confinement, which degrades the voltage of the cell. Recently, a new type of solution-processed semiconductor materials, quantum dots in a perovskite host (CQDs@Perovskite), has been demonstrated. The intrinsic opto-electronic properties of CQDs@Perovskite (high absorbance & strong quantum confinement) make them perfect candidates as absorber material in IBSCs. ENLIGHTEN will exploit CQDs@Perovskite materials combined with microstructure-based light trapping techniques to pave the way for low-cost high-efficiency solar cells. In addition, the cells have an innovative device structure compatible with flexible-substrate technology.