Dual-Electrically Configurable MoTe₂/In₂S₃ Phototransistor toward Multifunctional Applications

Area of Science:

• Optoelectronics and Materials Science
• Semiconductor Device Physics

Background:

• Photodetectors are crucial for optoelectronics but face trade-offs in performance metrics like responsivity and response time.
• Existing photodetectors are limited by unidirectional carrier transport, hindering multifunctional capabilities.

Purpose of the Study:

• To engineer a multifunctional photodetector with switchable operating modes.
• To overcome the limitations of traditional photodetectors by enabling dual electrical modulation.
• To demonstrate advanced applications leveraging the device's unique characteristics.

Main Methods:

• Fabrication of a 2D MoTe2/In2S3 heterostructure.
• Utilizing dual electrical modulation (bias and gate voltage) to control energy band engineering.
• Characterizing device performance in both photoconductive and photovoltaic modes.

Main Results:

• Achieved switchable photoresponse mechanisms between photoconductive and photovoltaic modes.
• Photoconductive mode: responsivity of 320 A/W, detectivity of 1.2 × 10^13 Jones.
• Photovoltaic mode: light on/off ratio of 2 × 10^5, response speed of 0.68/0.60 ms.

Conclusions:

• The developed multimodal phototransistor demonstrates significant advancements in optoelectronic device design.
• The device enables versatile applications including high-resolution imaging, optoelectronic logic gates, and dual-channel optical communication.
• This work paves the way for next-generation multifunctional optoelectronic systems.