Optimized performance III-nitride-perovskite-based heterojunction photodetector via asymmetric electrode configuration

Bottom-Up Formation of III-Nitride Nanowires: Past, Present, and Future for Photonic Devices

The realization of semiconductor heterostructures marks a significant advancement beyond silicon technology, driving progress in high-performance optoelectronics and photonics, including high-brightness light emitters, optical communication, and quantum technologies. In less than a decade since 1997, nanowires research has expanded into new application-driven areas, highlighting a significant shift toward more challenging and exploratory research avenues. It is therefore essential to reflect on the past motivations for nanowires development, and explore the new opportunities it can enable. The advancement of heterogeneous integration using dissimilar substrates, materials, and nanowires-semiconductor/electrolyte operating platforms is ushering in new research frontiers, including the development of perovskite-embedded solar cells, photoelectrochemical (PEC) analog and digital photonic systems, such as PEC-based photodetectors and logic circuits, as well as quantum elements, such as single-photon emitters and detectors. This review offers rejuvenating perspectives on the progress of these group-III nitride nanowires, aiming to highlight the continuity of research toward high impact, use-inspired research directions in photonics and optoelectronics.

Improvement of Self-Driven Nanowire-Based Ultraviolet Photodetectors by Metal-Organic Frameworks for Controlling Humanoid Robots

Self-driven photodetectors (PDs) hold significant potential for the development of new information devices, which boast the advantages of ultralow power consumption and straightforward fabrication. In this study, we have proposed and demonstrated a self-driven ultraviolet PD utilizing gallium nitride/metal-organic framework (GaN/MOF) heterojunction nanowires successfully. By introducing Gd-ETTC MOFs on the surface of GaN nanowires, the photocurrent and responsivity of the device can be improved by approximately 75% under 310 nm illumination. Furthermore, they can also be effectively enhanced under visible light illumination. Owing to the appropriate energy level alignment, Gd-ETTC MOFs can serve as both a light harvester and a hole conductor, facilitating the efficient absorption, separation, and transmission of photogenerated carriers. It has been observed that due to reduced interface resistance, MOFs can enhance the charge transport through the acceleration of charge transfer. Furthermore, the PD equipped with MOFs is capable of continuous operation for 30,000 s, a feat attributable to the exceptional stability of both GaN nanowires and Gd-ETTC MOFs. By implementation of the humanoid robot systems, the control commands from the self-driven PD can drive the humanoid robot to execute different actions. The PD-equipped autonomous feedback system of a humanoid robot enables a seamless integration of light perception with intelligent robotic actions. Therefore, the design and demonstration of GaN/MOF nanowires hold significant reference value for further enhancing the performance of PDs and broadening their applications in ultralow-power artificial intelligence systems, humanoid intelligent robots, etc.

Visible-ultraviolet dual-band photodetectors based on an all-inorganic CsPbCl3/p-GaN heterostructure

All-inorganic metal halide perovskites (MHPs) have attracted increasing attention because of their high thermal stability and band gap tunability. Among them, CsPbCl3 is considered a promising semiconductor material for visible-ultraviolet dual-band photodetectors because of its excellent photoelectric properties and suitable band gap value. In this work, we fabricated a visible-ultraviolet dual-band photodetector based on a CsPbCl3/p-GaN heterojunction using the spin coating method. The formation of the heterojunction enables the device to exhibit obvious dual-band response behavior at positive and negative bias voltages. At the same time, the dark current of the device can be as low as 2.42 × 10-9 A, and the corresponding detection rate can reach 5.82 × 1010 Jones. In addition, through simulation calculations, it was found that the heterojunction has a type II energy band arrangement, and the heterojunction response band light absorption is significantly enhanced. The type II energy band arrangement will separate electron-hole pairs more effectively, which will help improve device performance. The successful implementation of visible-ultraviolet dual-band photodetectors based on a CsPbCl3/p-GaN heterojunction provides guidance for the application of all-inorganic MHPs in the field of multi-band photodetectors.

Broadband Photodetector for Ultraviolet to Visible Wavelengths Based on the BA2PbI4/GaN Heterostructure

Two-dimensional (2D) organic-inorganic hybrid perovskites (OIPs) have exhibited ideal prospects for perovskite photodetectors (PDs) owing to their remarkable environmental stability, tunable band gap, and structural diversity. However, most perovskites face the great challenge of a narrow spectral response. Integrating 2D OIPs with a suitable wide band gap semiconductor gives opportunities to broaden the response spectra. Here, a photodetector based on the BA2PbI4/GaN heterostructure with a broadband photoresponse covering from the ultraviolet (UV) to visible band is designed. We demonstrate that the device is capable of detecting in the UV region by p-GaN being integrated with BA2PbI4. The morphology and material optical properties of BA2PbI4 are characterized by transmission electron microscopy (TEM) and photoluminescence (PL). Additionally, the current-voltage (I-V) characteristics and photoresponses of the BA2PbI4/GaN heterojunction photodetector are investigated. The response spectrum of the photodetector is broadened from the visible to UV region, exhibiting good rectifying behavior in the dark conditions and a broadband photoresponse from the UV to the visible region. Additionally, the energy band is used to analyze the current mechanism of the BA2PbI4/GaN heterojunction PD. This study is expected to provide a new insight of optoelectronic devices by integrating 2D OIPs such as BA2PbI4 and wide-band-gap semiconductors such as GaN to broaden the response spectra.