Granum-like stacking structures with TiO2-graphene nanosheets for improving photo-electric conversion

Nailiang Yang, Yu Zhang, Jonathan E. Halpert, Jin Zhai, Dan Wang, Lei Jiang

Research output: Contribution to journalArticleResearchpeer-review

35 Citations (Scopus)

Abstract

Solar energy is commonly considered to be one of the most important forms of future energy production. This is due to its ability to generate essentially free power, after installation, with low environmental impact. Green plants, meanwhile, exhibit a process for light-to-charge conversion that provides a useful model for using solar radiation efficiently. Granum, the core organ in photosynthesis consists of a stack of ~10-100 thylakoids containing pigments and electrons acceptors. Imitating the structure and function of granum, stacked structures are fabricated with TiO2/graphene nanosheets as the thylakoids unit, and their photo-electric effect is studied by varying the number of layers present in the film. The photo-electric response of the graphene composites are found to be 20 times higher than that of pure TiO 2 in films with 25 units stacked. Importantly, the cathodic photocurrent changes to anodic photocurrent as the thickness increases, an important feature of efficient solar cells which is often ignored. Here graphene is proposed to perform similarly to the b6f complex in granum, by separating charges and transporting electrons through the stacked film. Using this innovation, stacked TiO2/graphene structures are now able to significantly increase photoanode thickness in solar cells without losing the ability to conduct electrons.

Original languageEnglish
Pages (from-to)1762-1770
Number of pages9
JournalSmall
Volume8
Issue number11
DOIs
Publication statusPublished - 11 Jun 2012
Externally publishedYes

Keywords

  • artificial granum
  • charge transport
  • graphene
  • photo-electric conversion
  • stacked structures
  • TiO

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