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Published on: June 23, 2018
Dual-mode switchable and reconfigurable Van der Waals phototransistor for multi-state image encryption
Yuanfang Yu1, Senyao Tang1, Nanjie Jiang1
1State Key Laboratory of Flexible Electronics (LoFE) & Institute of Advanced Materials (IAM), School of Materials Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing, China.
Light, Science & Applications
|July 1, 2026
Summary
This study introduces a novel dual-mode phototransistor using a PtTe2/WS2 heterostructure. This device enables efficient optoelectronic encryption through switchable modes, offering high sensitivity and low power consumption for advanced secure communication.
Area of Science:
- Materials Science
- Optoelectronics
- Nanotechnology
Background:
- Two-dimensional van der Waals (vdWs) heterostructures are crucial for optoelectronic encryption chips due to their sensitivity and low power needs.
- Existing vdWs phototransistors face challenges like high power consumption, channel interference, and limited integration.
Purpose of the Study:
- To demonstrate a dual-mode vdWs phototransistor based on a PtTe2/WS2 heterostructure.
- To enable switchable operation between photoconductive and photovoltaic modes for enhanced functionality.
- To advance optoelectronic encryption and secure optical communication.
Main Methods:
- Fabrication of a PtTe2/WS2 heterostructure phototransistor.
- Modulation of band alignment and carrier dynamics via bias control.
- Characterization of device performance in both photoconductive and photovoltaic modes.
Main Results:
- Achieved switchable operation between photoconductive and photovoltaic modes.
- Photoconductive mode: High responsivity (1.37 A/W).
- Photovoltaic mode: High detectivity (9.42 × 10^14 Jones), pW-level weak light detection, and high-speed response (μs range).
- Dual-mode operation enabled high on/off ratio (~10^5), four current states, optical logic gates, and multi-state image encryption.
Conclusions:
- The PtTe2/WS2 dual-mode phototransistor offers a versatile platform for multi-functional optoelectronic chips.
- The demonstrated device capabilities pave the way for enhanced secure optical communication technologies.
- This work addresses limitations of previous vdWs phototransistors, enabling more integrated and efficient optoelectronic solutions.
