Photovoltage memory effect in a portable Faradaic junction solar rechargeable device

Area of Science:

• Materials Science
• Electrochemistry
• Renewable Energy

Background:

• Two-electrode solar rechargeable devices offer promising large-scale solar energy storage solutions.
• Challenges include unclear dark output voltage mechanisms and low volumetric energy density, limiting practical applications.

Purpose of the Study:

• To investigate the photovoltage memory effect in a Si/CoO_x/KBi_(aq)/MnO_x Faradaic junction device.
• To elucidate the mechanism behind the dark output voltage and its impact on device performance.
• To achieve high performance and energy density in solar rechargeable devices.

Main Methods:

• Fabrication of a Si/CoO_x/KBi_(aq)/MnO_x Faradaic junction device.
• Development of an open circuit potential method for real-time monitoring of photocharge and dark discharge.
• Performance evaluation focusing on photovoltage memory effect and energy density.

Main Results:

• The device exhibits a photovoltage memory effect, where dark output voltage precisely records photovoltage.
• The developed method allows real-time monitoring of charge/discharge processes.
• Minimized interface energy loss leads to significantly improved device performance.
• A record dark volumetric energy density of ~1.89 mJ cm^-3 was achieved.

Conclusions:

• The photovoltage memory effect is key to enhancing solar rechargeable device performance.
• The findings provide guidance for improving existing devices and designing novel photoelectric devices.
• This research advances solar energy storage technology and opens avenues for new applications.