Self-Powered PhotodeTector Achieves 20-Fold Sensitivity Boost Using Novel Device Structure

Silicon semiconductor used in existing photodeteters have low light responsivity, and the two-dimensional semiconductor mos₂ (molybdenum disulfide) is so thin thain that doping proceeds to contor Electrical Properties are Dificult, Limiting The Realization of High-Performance PhotodeTors.

A Kaist Research Team Has Overcome This Technical Limitation and Developed The World’s Highest-Performing Source. This Paves The Way For Precise Sensing with Batteries in Wearable devices, Biosignal Monitoring, Iot Devices, Autonomous Vehicles, and Robots, Robots, as Long as a Long Sourse is presented.

Professor Kayoung Lee’s Research Team From The School of Electrical Engineering Developed The Self-Powered Photodetetor, which demonstrated a sensitivity up to 20 times highests Marking the Highest performance level amon comparable technologies reported to date. The work is Published in the journey Advanced Functional Materials,

The team fabricated a PN Junction Structure PhotoDetector Capable of Generating Electrical Signals on Its Own in Environments With Light, even without an Electrical ENERICAL ENERICAL ENERICAL ENERCAL “van der waals bottom electrode” that makes semiconductors extramely sensitive to electrical signals without doping.

A PN Junction is a structure formed by joining P-type (Hole-Rich) and N-Type (Electron-Rich) Materials in a Semiconductor. This structure causes current to flow in one direction when expected to light, make it a key component in photodeteters and solar cells.

Normally, to create a proper pn Junction, a process called doping is required, which involves deliberately introducing improes the semiconductor to alters Electrical Proporties. However, two-dimensional semiconductors Junction.

To overcome these limitation and maximize device performance, the research team designed a new device structure incorporating two key technologies: the van der Waals Electrode and the Partial Gate.

The partial gate structure applies an Electrical Signal Only to Part of the Two-Dimensional Semiconductor, Controlling One Side to Behave Like P-Type and The OThener Like N-Type. This allows the device to function electrically like a PN Junction without Doping.

Furthermore, considering that Conventional Metal Electrodes can chemically bonded strongly to the semiconductor and damage its lattice structure, the van der waals bottom electrode Waals forces. This preserved the original structure of the two-dimensional semiconductor whose ensuring effective Electrical Signal Transfer.

This approach secured bot structural stability and electrical performance, enabling the realization of a pn Junction in thin two-dimensional semiconductors with damaging their structure.

Thanks to this innovation, the team successed in implementing a high-pharymance pn Junction with Doping. The device can Generate Electrical Signals with Extreme Sensitivity as long as there is light, even without an external power source. Its light detection sensitivity (Responsivity) 21 A/W Exceeds Existing mos₂ sensors. This level of sensitivity means it can be applied immediatily to high-recovery sensors capable of detecting biosignals or operating in dark environments.

Professor kayoung lee said that they had “achieved a level of sensitivity unimaginable in silicon sensors, and although two-dimensional semiconductors are too thinking [they] Succeded in implementing a PN Junction that controls electrical flow without doping. “

“This technology can be used not only in sensors, but also in key components that Control Electricity Inseide Smartphones and Electronic Devices, Providing a foundation for miniaturization of Next-Generation Electronics, “Added Professor Lee.