High-performance near-infrared Schottky-photodetector based graphene/In2S3 van der Waals heterostructures

Advances in borophene based photodetectors for a sustainable tomorrow: a comprehensive review

Borophene, with its unique properties such as excellent conductivity, high thermal stability, and tunable electronic band structure, holds immense promise for advancing photodetector technology. These qualities make it an attractive material for enhancing the efficiency and performance of photodetectors across various wavelengths. Research so far has highlighted borophene's potential in improving sensitivity, response time, and overall functionality in optoelectronic devices. However, to fully realize the potential of borophene-based photodetectors, several challenges must be addressed. A major hurdle is the reproducibility and scalability of borophene synthesis, which is essential for its widespread use in practical applications. Furthermore, understanding the underlying physics of borophene and optimizing the device architecture are critical for achieving consistent performance under different operating conditions. These challenges must be overcome to enable the effective integration of borophene into commercial photodetector devices. A thorough evaluation of borophene-based photodetectors is necessary to guide future research and development in this field. This review will provide a detailed account of the current synthesis methods, discuss the experimental results, and identify the challenges that need to be addressed. Additionally, the review will explore potential strategies to overcome these obstacles, paving the way for significant advancements in solar cells, light-based sensors, and environmental monitoring systems. By addressing these issues, the development of borophene-based photodetectors could lead to substantial improvements in optoelectronic technology, benefiting various applications and industries.

Chemical Vapor Deposition Growth of Few-Layer β12-Borophane on Copper Foils toward Broadband Photodetection

Borophene has drawn tremendous attention in the past decade for a wide range of potential applications owing to its unique structural, optical, and electronic properties. However, applications of borophene toward next-generation nanodevices are mostly theoretical predictions, while experimental realization is still lacking due to rapid oxidation of intrinsic borophene in an air environment. Here, we have successfully prepared structurally stable and transferrable few-layer β₁₂-borophane on copper foils by a typical two-zone chemical vapor deposition method, where bis(triphenylphosphine)copper tetrahydroborate was used as the boron source in a hydrogen-rich atmosphere to stabilize its structure through hydrogenation. The crystal structure of the as-prepared β₁₂-borophane is in good agreement with previous reports. A fabricated photodetector based on β₁₂-borophane-silicon (n-type) Schottky junction shows good photoelectric responses to light excitations in a wide wavelength range from 365 to 850 nm. Especially, the photodetector exhibits a good photoresponsivity of around 0.48 A W^-1, a high specific detectivity of 4.39 × 10¹¹ jones, a high external quantum efficiency of 162%, and short response and recovery times of 115 and 121 ms under an ultraviolet light with the wavelength of 365 nm at a reverse bias of 5 V. The results show great potential applications of borophane in next-generation nanophotonic and nanoelectronic devices.

High responsivity graphene-InGaAs near-infrared photodetector realized by hole trapping and its response saturation mechanism

Graphene is an ideal material for wide spectrum detector owing to its special band structure, but its low light absorption and fast composite of photogenerated carriers lead to a weak response performance. In this paper, we designed a unique photoconductive graphene-InGaAs photodetector. The built-in electric field was formed between graphene and InGaAs, which can prolong the lifetime of photogenerated carriers and improve the response of devices by confining the holes. Compared with graphene-Si structure, a higher built-in electric field and reach to 0.54 eV is formed. It enables the device to achieve a responsivity of 60 AW^-1 and a photoconductive gain of 79.4 at 792 nm. In the 1550 nm communication band, the responsivity of the device is also greater than 10 AW^-1 and response speed is less than 2 ms. Meanwhile, the saturation phenomenon of light response was also found in this photoconductive graphene heterojunction detector during the experiment, we have explained the phenomenon by the capacitance theory of the built-in electric field, and the maximum optical responsivity of the detector is calculated theoretically, which is in good agreement with the measurement result.

Design and tailoring of two-dimensional Schottky, PN and tunnelling junctions for electronics and optoelectronics

Owing to their superior carrier mobility, strong light-matter interactions, and flexibility at the atomically thin thickness, two-dimensional (2D) materials are attracting wide interest for application in electronic and optoelectronic devices, including rectifying diodes, transistors, memory, photodetectors, and light-emitting diodes. At the heart of these devices, Schottky, PN, and tunneling junctions are playing an essential role in defining device function. Intriguingly, the ultrathin thickness and unique van der Waals (vdW) interlayer coupling in 2D materials has rendered enormous opportunities for the design and tailoring of various 2D junctions, e.g. using Lego-like hetero-stacking, surface decoration, and field-effect modulation methods. Such flexibility has led to marvelous breakthroughs during the exploration of 2D electronics and optoelectronic devices. To advance further, it is imperative to provide an overview of existing strategies for the engineering of various 2D junctions for their integration in the future. Thus, in this review, we provide a comprehensive survey of previous efforts toward 2D Schottky, PN, and tunneling junctions, and the functional devices built from them. Though these junctions exhibit similar configurations, distinct strategies have been developed for their optimal figures of merit based on their working principles and functional purposes.