A Capacitor-type Faradaic Junction for Direct Solar Energy Conversion and Storage

Two-electrode solar rechargeable devices trigger intense attention due to their potential applications in solar energy conversion and storage. However, interface energy barriers lead to severe loss of output voltage and negligible dark discharge current. Therefore, external biases are required for dark discharge in these devices, limiting their practical applications. Herein, we report a new two-electrode device of Si/WO3/H2SO4(aq)/C that can work without bias. The device has the highest dark output power among all of the two-electrode solar rechargeable devices. The device based on a Si/WO3 junction indicates photoinduced adjustable interface barrier height during charge transfer, which can overcome the energy barrier and realize dark discharge without bias. Owing to the interface characteristics, the Si/WO3 is designated as a capacitor-type Faradaic junction.

Automated summary

A new two-electrode solar rechargeable device based on Si/WO3 junction is reported, which can achieve dark discharge without bias and has the highest dark output power among all two-electrode devices. The device exhibits photoinduced adjustable interface barrier height during charge transfer, overcoming energy barriers and realizing dark discharge without bias. The Si/WO3 is designated as a capacitor-type Faradaic junction due to its interface characteristics.