High sensitivity Si-based photodetection with nanoscale protective layer based on interface states

Area of Science:

• Materials Science
• Semiconductor Physics
• Optoelectronics

Background:

• Traditional photovoltaic devices rely on Schottky or PN junctions.
• Interface states at semiconductor/insulator boundaries can influence electronic properties.
• Silicon dioxide (SiO2) on silicon (Si) interfaces are crucial in semiconductor technology.

Purpose of the Study:

• To investigate a large lateral photovoltaic effect in a SiO2/p-Si/SiO2 structure.
• To elucidate the role of interface states in photovoltage generation.
• To analyze factors influencing photovoltage output and sensitivity.

Main Methods:

• Fabrication of a SiO2/p-Si/SiO2 device structure.
• Characterization of the lateral photovoltaic effect.
• Analysis of the impact of oxide thickness, resistivity, and tunneling on device performance.

Main Results:

• A significant lateral photovoltaic effect was observed at the SiO2/p-Si interface.
• Photovoltage generation is primarily governed by interface states, not traditional junctions.
• Device performance is stabilized and enhanced by the nanoscale SiO2 layer.

Conclusions:

• Interface states, acting as a built-in field due to band bending, regulate photo-induced carrier dynamics.
• Oxide thickness, resistivity, and tunneling effects critically impact photovoltage output and sensitivity.
• This simple SiO2/p-Si/SiO2 structure presents a promising platform for photoelectric detection.