Torsional monopole barrier heterojunction devices simplify optical imaging and sensing

Polarized light is the fundamental property of light, along with intensity, wavelength and phase. Enhance imaging contrast and resolution compared to traditional intensity-based methods. On-chip polarizers rely on complex 4-pixel arrays or external polarizers.

Current solutions face two important challenges: limited spectral responses in plasmonic and metasurface-based devices and the difficulty in simultaneously detecting the angle of linear polarization (AOLP) and degree (DOLP) in low-dimensional anisotropic materials. Achieving wide range of high-precision polarization detection remains an important issue in this field.

To address this, a research team led by Professor Li Liang of the Hefei Institutes of Solid State Physics, the HEFEI Institute of Science at the Chinese Academy of Sciences, collaborated with Professor Zhai Tianyou of Huazhong Science and Technology to develop a novel “Torsion unipolar Barrier heterojunction” device.

Their findings were recently published in Advanced Materials.

This innovative device utilizes the unique anisotropic photoelectric properties of two-dimensional PDSE₂ to create a double absorbing layer while fine tuning the energy band of the intermediate moss barrier layer. This design allows for bias-programmable control of carrier transport paths, leading to groundbreaking performance.

There are two important advances in this device:

The bipolar current behavior at zero bias allows for direct decoding of polarized encoded bibinary communication signals. It eliminates the need for auxiliary polarizers that allow for real-time simultaneous measurements of AOLP and DOLP, and overcomes the limitations of traditional 4-pixel arrays.

The research, according to the team, provides a new perspective on next-generation on-chip polarization detectors, enhancing optical information processing while simplifying device structure.