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- Chip Highlights Bao Wenzhong's Team's Breakthrough: Universal Optoelectronic Imaging Platform Using 2D Semiconductors
Chip Highlights Bao Wenzhong's Team's Breakthrough: Universal Optoelectronic Imaging Platform Using 2D Semiconductors
Recently, Bao Wenzhong's team from Fudan University published a research paper titled "A universal optoelectronic imaging platform with wafer-scale integration of two-dimensional semiconductors "¹ on Chip . They developed a wafer-level integrated universal optoelectronic imaging platform based on two-dimensional semiconductor materials, realizing a high-performance, multi-functional and large-scale integrated imaging system. The first authors are Fudan University's doctoral students Wang Xinyu, Wang Die, and Tian Yuchen, and the corresponding authors are Bao Wenzhong (Fudan University, Shaoxin Laboratory), Chen Honglei (Shanghai Institute of Technical Physics, Chinese Academy of Sciences), and Shao Lei (Soochow University). Chip is the world's only comprehensive international journal focusing on chip research, and is one of the "three types of high-quality papers" journals selected for the National High-Starting Point New Journal Program.
This study focuses on the development of a wafer-level integrated universal optoelectronic imaging platform based on two-dimensional semiconductor materials. The research team adopted a variety of innovative methods to achieve this goal. First, they selected a variety of two-dimensional materials, including MoS₂, MoTe₂, etc., which have unique optoelectronic properties. In order to promote the efficient integration of two-dimensional materials with traditional silicon-based electronic devices, researchers have innovatively developed wafer-level integration preparation technology². This technology breaks through traditional boundaries and can directly grow large-area and high-quality two-dimensional material films on a pre-designed substrate, achieving seamless and highly compatible integration between the two, opening up a new path for improving the performance of electronic devices³⁻⁴ .
Figure 1 | Photoconductive (PC) and photovoltaic (PV) properties. Schematic diagram of the structure of a typical PC ( a ) and PV ( d ) photodetector. Schematic diagram of the energy band arrangement of PC ( b ) and PV ( c ) photodetectors under illumination. d (i) Metal semiconductor contact structure, d (ii) Vertical PN junction structure based on two-dimensional materials, d (iii) Horizontal PN junction structure based on two-dimensional materials, d (iv) PN junction structure composed of P-type two-dimensional materials and N-type silicon. I – V of PC ( e (i)) and PV ( e (ii)) photodetectors in the dark and under illumination Characteristics; ( f ) Workflow of the general testing system.
During the device manufacturing process, the research team also optimized the design of the readout circuit ( CMOS ) to ensure that it matches the characteristics of the two-dimensional material detector. They used advanced micro-nano processing technology to make electrodes and interconnect structures to ensure the high performance and reliability of the device. In addition, the researchers also developed special packaging technology to protect sensitive two-dimensional materials from environmental factors, thereby extending the service life of the device.
Figure 2 | Characteristics of photodetector devices. Structural diagram and optical microscope images of PC ( a ) and PV ( b ) photodetector devices. PC ( c , d ) and PV ( e , f ) photodetector devices in the dark state and at different wavelengths and light intensities.I – VCharacteristics. Temporal photocurrent characteristics of PC ( g , h ) and PV ( i , j ) photodetectors at different wavelengths and light intensities .
The team successfully manufactured a large-scale integrated two-dimensional semiconductor photodetector array, achieving high-resolution and high-frame-rate imaging of more than 100 frames per second. This system is not only capable of conventional visible light imaging but also works in the near-infrared and short-wave infrared bands, demonstrating excellent multispectral imaging capabilities. It is particularly worth mentioning that the researchers achieved high-quality color imaging, near-infrared night vision imaging, and short-wave infrared material recognition imaging through carefully designed optical systems and signal processing algorithms.
Figure 3 | Readout circuit (ROIC) structure and coupling system. a, Schematic diagram of the printed circuit board used for coupling. b, Partition layout module of the readout circuit. c, Schematic diagram of the detector in an mxn array. Internal overall circuit design diagram of the PC ( d ) and PV ( e ) detectors .
The research team conducted an in-depth analysis of the advantages and potential applications of this new imaging platform. Compared with traditional silicon-based image sensors, this two-dimensional material-based platform has a wider spectral response range and can achieve multi-band imaging on a single chip. This feature has important applications in many fields, such as simultaneously acquiring surface and deep tissue information in medical imaging, and identifying different gases and pollutants monitoring⁵⁻⁶ .
Figure 4 | Integration of photodetector and ROIC . a, Experimental setup of the imaging system. b, Basic principle of line scan imaging and grayscale mapping relationship. c, Different stages of the imaging process.
In addition, the researchers also explored the scalability and industrialization prospects of this technology. They pointed out that although the current manufacturing cost is high, with the advancement of two-dimensional material production technology and the emergence of economies of scale, the cost is expected to be greatly reduced. The team also proposed several improvement directions, including further improving material quality, optimizing device structure, and developing more advanced signal processing algorithms to further enhance system performance.
Finally, the researchers looked forward to the future development of this technology. They believe that with the continuous advancement of two-dimensional material science and engineering, this universal optoelectronic imaging platform is expected to find applications in more fields, such as autonomous driving, augmented reality, industrial inspection, etc. This research not only promotes the application of two-dimensional materials in the field of optoelectronics but also points the way for the development of the next generation of multifunctional, high-performance imaging systems.