Grigioni, I., Polo, A., Dozzi, M. V., Stamplecoskie, K. G., Jara, D. H., Kamat, P. V., et al. (2022). Enhanced Charge Carrier Separation in WO3/BiVO4 Photoanodes Achieved via Light Absorption in the BiVO4 Layer. ACS Appl. Energy Mater., 5(11), 13142–13148.
Abstract: Photoelectrochemical (PEC) water splitting converts solar light and water into oxygen and energy-rich hydrogen. WO3/BiVO4 heterojunction photoanodes perform much better than the separate oxide components, though internal charge recombination undermines their PEC performance when both oxides absorb light. Here we exploit the BiVO4 layer to sensitize WO3 to visible light and shield it from direct photoexcitation to overcome this efficiency loss. PEC experiments and ultrafast transient absorption spectroscopy performed by frontside (through BiVO4) or backside (through WO3) irradiating photoanodes with different BiVO4 layer thickness demonstrate that irradiation through BiVO4 is beneficial for charge separation. Optimized electrodes irradiated through BiVO4 show 40% higher photocurrent density compared to backside irradiation.
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Werlinger, F., Segura, C., Martinez, J., Osorio-Roman, I., Jara, D., Yoon, S. J., et al. (2023). Current Progress of Efficient Active Layers for Organic, Chalcogenide and Perovskite-Based Solar Cells: A Perspective. Energies, 16(16), 5868.
Abstract: Photovoltaics has become one of the emerging alternatives to progressively supply/replace conventional energy sources, considering the potential exploitation of solar energy. Depending on the nature of the light harvester to influence on its light-absorption capability and the facility to produce electricity, different generations of solar devices have been fabricated. Early studies of organic molecules (dye sensitizers) with good absorption coefficients, going through metal chalcogenides and, lastly, the timely emergence of halide perovskites, have promoted the development of novel and low-cost solar cells with promising photoconversion efficiency (PCE), close to the well-established Si-based devices. However, main drawbacks such as the degradation/photocorrosion of the active layer, the existence of intrinsic defect sites, and the inherent toxicity of the material due to the presence of some harmful elements have blocked the future commercialization of the above kind of solar cells. In this review, we highlight the current progress in achieving efficient photomaterials for organic, chalcogenides and halide perovskites-based solar cells with the purpose of achieving high PCE values, some of which are breakthroughs in this research topic, and the diverse approaches used to extend the stability of the active layer and improve the performance of the solar devices.
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