High-Efficiency Selective Electron Tunnelling in a Heterostructure Photovoltaic Diode

Area of Science:

• Materials Science
• Nanotechnology
• Photovoltaics

Background:

• Conventional photovoltaic devices face limitations in charge separation and transport efficiency.
• Graphene's unique electronic properties offer potential for enhanced optoelectronic device performance.

Purpose of the Study:

• To design and characterize a novel all-solid-state heterostructure photovoltaic diode.
• To investigate the charge separation and transport mechanisms at a TiO2/graphene/dye interface.
• To demonstrate a new device architecture for efficient photon-to-electricity conversion.

Main Methods:

• Fabrication of a ternary heterostructure photovoltaic device with TiO2, graphene, and dye components.
• Utilizing dye molecules as photoreceptors for light absorption and photoexcited charge generation.
• Investigating the charge transport dynamics using the ipsilateral selective electron tunnelling (ISET) mechanism.

Main Results:

• Achieved high-efficiency photogenerated charge separation and transport through the TiO2/graphene/dye interface.
• Demonstrated efficient ballistic electron transport in graphene toward the TiO2 layer.
• A model device achieved ~86.8% interfacial separation/collection efficiency and ~80% absorbed photon-to-current efficiency (APCE).

Conclusions:

• The developed heterostructure photovoltaic device exhibits a novel ISET mechanism for efficient photon-to-electricity conversion.
• This device architecture offers advantages in efficiency, fabrication, scalability, and material cost.
• The ISET-based photovoltaic device holds promise for solar cells, photoelectric detectors, and other optoelectronic applications.