Special issue-Novel infrared detection technology driven by local field

Research progress on local field characterization of mercury cadmium telluride infrared photodetectors (invited)
Liu Shuning, Tang Qianying, Li Qing
2022, 51(7): 20220277. doi: 10.3788/IRLA20220277
[Abstract](237) [FullText HTML] (44) [PDF 2134KB](84)
Mercury cadmium telluride (HgCdTe) material is an important detection material used in third-generation infrared detection systems, and its development level can reflect the optimal performance indicators of current infrared detectors. In recent years, astronomical, remote sensing, and civil equipment have put forward higher requirements for detector performance, which has brought new challenges to the design and preparation of HgCdTe infrared detectors. The finer design and processing technology of HgCdTe infrared detectors provide solutions for improving the performance of HgCdTe infrared detectors. Suppressing the harmful local field of the device and regulating the beneficial local field of the device can achieve further breakthroughs in device performance. However, how to characterize and analyse the local field of HgCdTe optoelectronic devices and clarify the origin of dark current and related noise in HgCdTe optoelectronic devices have become key scientific and technical issues to be solved to promote device performance breakthroughs. This paper summarizes the research progress of local field characterization and analysis of HgCdTe infrared photodetectors and provides basic support for the development of a new generation of HgCdTe infrared photodetectors.
Research progress on ferroelectric localized field-enhanced low-dimensional material-based photodetectors (invited)
Yu Chenhui, Shen Niming, Zhou Yong, Cheng Tiantian, Qin Jiayi, Luo Man
2022, 51(7): 20220288. doi: 10.3788/IRLA20220288
[Abstract](216) [FullText HTML] (53) [PDF 3195KB](93)
Photodetectors are widely used in daily life and national security, including communication, the environment, health and national defense. With the development of time, the performance requirements of photodetectors in terms of sensitivity, response speed and wavelength range have been increasing. The unique electrical and optoelectronic properties of low-dimensional materials make them an essential application prospect in the field of optoelectronic devices. To make full use of the advantages of low-dimensional materials and overcome the shortcomings of high dark current and low absorption rate, researchers have combined ferroelectric materials with low-dimensional materials and used the remnant polarization of ferroelectric materials to form a strong localized field to modulate carriers, which improves the photodetection capability of low-dimensional materials. Recent research results of ferroelectric localized field-enhanced low-dimensional material-based photodetectors are summarized in this paper. Meanwhile, related research on the modulation and performance enhancement of ferroelectric materials in one-dimensional nanowires, two-dimensional materials and junction devices was introduced. Finally, the development trend of ferroelectric localized field-enhanced low-dimensional material-based photodetectors was briefly summarized and proposed.
Recent advances in two-dimensional materials in infrared photodetectors (invited)
Jia Xinyu, Lan Changyong, Li Chun
2022, 51(7): 20220065. doi: 10.3788/IRLA20220065
[Abstract](270) [FullText HTML] (65) [PDF 4507KB](104)
Two-dimensional (2D) materials, which have a thickness on the atomic scale, have attracted wide attention due to their unique physical and chemical properties. Because of their high carrier mobility, strong light-matter interaction, and anisotropic electronic/optical properties, etc., 2D materials show promising applications in optoelectronics. Among the 2D materials, narrow band gap semiconductors, such as black phosphorus, black arsenic phosphorus, etc., have shown huge potential in infrared photodetectors and have become star materials in infrared photodetectors. In this review, recent advances in 2D materials in infrared photodetectors are introduced, with an emphasis on photodetectors depending on the inner photoelectronic effect. First, the background of 2D materials is introduced. Then, the key parameters for infrared photodetectors, such as the responsivity, quantum efficiency, specific detectivity, and response speed, are listed. This is followed by the presentation of the recent advances of 2D materials in infrared photodetectors, which is divided into three parts: single component 2D material photodetectors, heterostructure infrared photodetectors, and waveguide photodetectors. Finally, a summary and outlook are provided for a guideline. We hope the present review will show the huge potential of 2D materials in infrared photodetectors and attract more exciting work on infrared photodetectors based on 2D materials in the future.
Near-field nano-imaging of graphene Moiré superlattices (invited)
Sun Qiaodong, Huang Xinyu, Lin Runfeng, Peng Zhuiri, Xu Langlang, Ye Lei
2022, 51(7): 20211118. doi: 10.3788/IRLA20211118
[Abstract](93) [FullText HTML] (31) [PDF 1834KB](40)
Two-dimensional materials with excellent photoresponse have presented high potential in new-type infrared photodetection technologies. Introducing a localized field into two-dimensional infrared photodetectors can greatly enhance their photodetection performance. An infrared detection technique is presented based on the photothermoelectric effect through twisted bilayer graphene Moiré superlattices. The formation of the Moire superlattice alters the Seebeck coefficient of the system and the concentration of hot carriers. Applying a high-resolution photocurrent tip is capable of detecting photoresponse of a single Moire unit cell, thereby obtaining a high-resolution photocurrent map of the whole twisted bilayer graphene system. This technique demonstrates the prospect of spintronics in the field of photodetection, and provides a novel pattern for designing future single-photon detectors.
Multimode resonance triple-band metamaterial absorber from mid-infrared to very long wavelengths (invited)
Qin Zheng, Liang Zhongzhu, Shi Xiaoyan, Yang Fuming, Liu Wenjun, Hou Enzhu, Meng Dejia
2022, 51(7): 20220224. doi: 10.3788/IRLA20220224
[Abstract](108) [FullText HTML] (22) [PDF 3089KB](57)
Metamaterial absorbers can confine and completely absorb incident electromagnetic waves to the subwavelength scale and have promising applications in detection, thermal emitters, energy harvesting, cooling, etc. The multiband metamaterial absorbers reported thus far are mainly the perfect absorption of multiple similar wavelengths in a specific wavelength range. Achieving multiwavelength absorption over a wide spectral range requires the combined work of multiple structures. Based on the three-layer structure of the titanium cross resonator-silicon nitride dielectric layer-titanium reflective layer, a triple-band metamaterial absorber with operating wavelengths spanning midwave infrared, longwave infrared, and very longwave infrared was designed and numerically simulated. Using the propagating surface plasmon resonance, the localized surface plasmon resonance, and the silicon nitride intrinsic absorption mode excited by the metamaterial absorber, high absorption reached 97.3%, 94.4%, and 93.6% at wavelengths of 4.8 μm, 9.1 μm and 18 μm respectively. Meanwhile, the wavelengths of the three absorption peaks can be flexibly manipulated by changing the geometric parameters of the metamaterial absorber, and the absorber exhibits insensitivity to polarization and incident angle. The materials used in this work are commonly used in existing processes and have application prospects in gas detection and infrared imaging.
Fabrication and characterization of ridge waveguide in MgF2 crystal at mid-infrared 4 μm wavelength (invited)
Li Shuhui, Song Hongxiao, Cheng Yazhou
2022, 51(7): 20220441. doi: 10.3788/IRLA20220441
[Abstract](106) [FullText HTML] (14) [PDF 2045KB](26)
To study the mechanism of interaction between ions and mid-infrared crystals and explore the preparation and properties of mid-infrared crystal optical waveguides, an optical ridge waveguide with a depth of 17.5 μm and a width of 14 μm was fabricated in MgF2 crystals by ion irradiation combined with precision diamond blade dicing. The SRIM software was used to simulate the process of electronic and nuclear stopping powers of MgF2 crystal irradiated by C5+ ions, and the mechanism of waveguide formation was analysed. The refractive index variation of the waveguide was simulated, and the near-field mode of the waveguide was experimentally measured and theoretically simulated. The propagation loss of the waveguide was reduced to 0.4 dB/cm by thermal annealing. The micro-Raman spectra show that there was no significant lattice damage in the waveguide region of the MgF2 crystal during ion irradiation. The results show that ion irradiation combined with diamond dicing is a very mature method to prepare ridge waveguides, and the prepared MgF2 crystal ridge waveguides have a wide application prospects in the field of mid-infrared integrated optics and optical communication.