Reconfigurable two-dimensional optoelectronic devices enabled by local ferroelectric polarization.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional (2D) semiconductors offer unique electronic properties for novel devices.
• Ferroelectric materials provide tunable polarization for device engineering.
• Achieving controlled doping in 2D materials is crucial for device functionality.

Purpose of the Study:

• To demonstrate ferroelectric-induced pn doping in molybdenum disulfide (MoS2).
• To engineer MoS2-based lateral diodes and npn bipolar phototransistors.
• To investigate the photodetection performance of these reconfigurable devices.

Main Methods:

• Utilizing local patterned ferroelectric polarization to achieve pn doping in MoS2.
• Fabricating lateral pn diodes and npn bipolar phototransistors.
• Characterizing device performance including self-powered detection, gain, responsivity, detectivity, and response speed.

Main Results:

• Successful pn doping in MoS2 via ferroelectric polarization.
• Lateral pn diodes achieved efficient self-powered photodetection with ~12% charge separation.
• Bipolar phototransistors exhibited high gain (~1000), responsivity (~12 A/W), and detectivity (>10^13 Jones) with fast response (<20 μs).

Conclusions:

• Ferroelectric polarization is a versatile method for reconfigurable doping in 2D semiconductors.
• This approach enables the creation of high-performance, customized optoelectronic devices.
• Opens new avenues for advanced photodetectors and transistors based on 2D materials.