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A GQD-based composite film as photon down-converter in CNT/Si solar cells


Graphene quantum dots (GQDs), have unique quantum confinement effects, tunable bandgap and luminescence property, with a wide range of potential applications such as optoelectronic and biomedical areas. However, GQDs usually have a strong tendency toward aggregation especially in making solid films, which will degrade their optoelectronic properties, for example, causing undesired fluorescence quenching. Here, we designed a composite film by embedding GQDs in a polyvinyl pyrrolidone (PVP) matrix through hydrogen bonding with well-preserved fluorescence, with a small addition of acid for compensating the poor conductivity of PVP. As a multifunctional solid coating on carbon nanotube/silicon (CNT/Si) solar cells, the photon down-conversion by GQDs and the PVP anti-reflection layer for visible light lead to enhanced external quantum efficiency (by 12.34% in the ultraviolet (UV) range) and cell efficiency (up to 14.94%). Such advanced optical managing enabled by low-cost, carbon-based quantum dots, as demonstrated in our results, can be applied to more versatile optoelectronic and photovoltaic devices based on perovskites, organic and other materials.


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A. Y. C. acknowledged the support from the National Natural Science Foundation of China (NSFC) (No. 51672005) and the National Key R&D Program of China (No. 2017YFA0206701). Y. Y. S. acknowledged the National Natural Science Foundation of China (NSFC) (No.51872267). X. W. Z. thanked Qihang Gong for his encouragement and support all the time.

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Correspondence to Yuanyuan Shang or Anyuan Cao.

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Zhao, X., Wu, Y., Xia, Z. et al. A GQD-based composite film as photon down-converter in CNT/Si solar cells. Nano Res. 14, 3893–3899 (2021).

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  • graphene quantum dots
  • polyvinyl pyrrolidone
  • energy-down-shift
  • external quantum efficiency
  • CNT/Si solar cells