Design Optimization and Characterization with Fabrication of Nanomaterials-Based Photo Diode Cell for Subretinal...

Area of Science:

• Biomedical Engineering
• Materials Science
• Ophthalmology

Background:

• Photoreceptor degeneration from conditions like Age-related Macula Degeneration (AMD) and Retinitis Pigmentosa (RP) leads to vision loss.
• Silicon-based artificial retinas face challenges due to implant rigidity.
• Organic photovoltaic cells offer a flexible alternative, but require improved electrode materials and active layer stability.

Purpose of the Study:

• To fabricate and characterize a novel Bulk Hetero Junction (BHJ) based Nano Photo Diode (NPD) for subretinal prosthesis.
• To address limitations of existing artificial retina technologies, including Indium-Tin Oxide (ITO) use and active layer delamination.
• To explore alternative materials for transparent conductive electrodes and active layers in flexible photodiode arrays.

Main Methods:

• Fabrication of a BHJ Nano Photo Diode (NPD) using a Graphene-polyethylene terephthalate (G-PET) anode, a semiconducting Single-Wall Carbon Nano Tubes (s-SWCNT): fullerene (C60) active layer, and an aluminum cathode.
• Characterization of the NPD device performance, focusing on power conversion efficiency.
• Investigation of material properties and device architecture for improved subretinal prosthesis.

Main Results:

• Successful fabrication of a non-ITO-driven NPD with a power conversion efficiency of 10.1%.
• Demonstrated the potential of G-PET as a transparent conductive electrode alternative to ITO.
• Identified active layer thickness as a factor for further efficiency improvements.

Conclusions:

• The developed G-PET/s-SWCNT:C60/Al NPD structure shows significant promise as a flexible artificial retina component.
• This research provides a viable, non-ITO alternative for subretinal prosthesis, potentially overcoming limitations of current technologies.
• Further optimization of active layer thickness can enhance the efficiency of these novel photodiode arrays for therapeutic applications.