Self-powered Photodetector Research Articles

Improved photoresponse performance of self-powered solar-blind UV photodetectors based on n-Si/n-Ga2O3/p-Li:NiO dual-junction

The solar-blind photodetectors (SBPDs) based on the wide-bandgap semiconductor gallium oxide (Ga2O3) exhibit significant potential for applications in military, civilian, and medical fields. Although multiple structural designs of Ga2O3-based SBPDs have been proposed, their performance typically falls short of commercial standards. However, the photoresponse speed of most self-powered PDs decreases rapidly in the solar-blind region. To address this issue, we first prepared high-quality single-crystal β-Ga2O3 films using RF magnetron sputtering, which exhibit an average transmittance exceeding 85% across the 400–800 nm range and possess a relatively smooth surface. Subsequently, a superior performance self-powered SBPD of vertical structure of n-Si/n-Ga2O3/p-Li:NiO dual-junction was fabricated, which possesses a responsivity of 0.18 mA/W, a photo-to-dark current ratio of 395, rapid rise/decay times of 132/148 ms, and a specific detectivity of 1.57 × 109 Jones at 0 V bias under 254 nm illumination. The photocurrent of the device fully recovered to its initial level after experiencing changes in ambient temperature [from room temperature (RT) to 100 °C and back to RT], demonstrating robust stability in harsh environments. In addition, the valence band structures of p-Li:NiO and n-Ga2O3 were investigated in detail using XPS, and the working mechanism of the devices was analyzed based on the Fermi level alignment. The excellent performance of PDs can be attributed to the increased depletion layer width, which generates more photogenerated carriers. Additionally, the separation and transmission of photo-induced carriers are enhanced by the superposition of a double built-in electric field. Our strategy offers a promising approach for achieving high-performance Ga2O3-based photovoltaic PDs.

Multilayered heterojunction-based zinc oxide nanoneedles/polyaniline/titania nanoparticles as a self-powered ultraviolet light photodetector

Nowadays, self-powered ultraviolet photodetectors (SPDs) with improved photoresponse features have attracted considerable attention due to their great pivotal applications in military and civilian fields. In the present work, for the first time, we investigate and report the construction and photoresponse features of a SPD based on multilayered heterojunction-based zinc oxide nanoneedles/polyaniline/titania nanoparticles (ZET). The structure, morphology, and optical properties of the ZET and its components were comprehensively investigated. A significant dependence was observed between the changes in I-V characteristics of the ZET-based SPD (SPZ) and the temperature change, resulting in a short reverse saturation current, proper ideality factor, and low dark current. I-V characteristics of the SPZ revealed nonlinear asymmetric rectifying behavior with the improved current under the influence and increase of power densities (PDiss) of ultraviolet (UV) light irradiation. Moreover, the self-powered feature of the SPZ was confirmed by the generation of short-circuit current and notable contrast ratio under UV light illumination at zero bias voltage. The device displayed remarkable photoresponsivity of 4.46A/W, high significant normalized detectivity of 63.1×1012Jones, good fill factor of 50.64%, and excellent external quantum efficiency of 1514% at the PDis of 0.77mW/cm2. In addition, the SPZ exposed a short rise time of 540 ms, a high maximum photocurrent of 99.9µA, and a significant gain dynamic range of 499.5 at PDis of 19.11mW/cm2. Finally, the imaginable mechanism of the current generation in our hand-made device was discussed in detail by exerting a standard thermionic emission-diffusion model and energy band diagram.

Self-Powered Solar-Blind Photodetectors and Arrays Based on Honeycomb-Grid Transparent Conductive Electrodes

Self-Powered Solar-Blind Photodetectors and Arrays Based on Honeycomb-Grid Transparent Conductive Electrodes

Self-Powered Photodetectors with High Stability Based on Se Paper/P3HT:Graphene Heterojunction

Self-Powered Photodetectors with High Stability Based on Se Paper/P3HT:Graphene Heterojunction

Single-Crystalline Nanowires of Molecular Ferroelectric Semiconductors for Optoelectronic Memory

Though much progress has been achieved in the discovery of new molecular ferroelectrics in recent years, practical applications and related physics are still rarely explored due to the difficulty in high-quality film production and patterning issues. Single-crystalline films and patterns are in high demand for high device performance. Through a template-assisted space-confined strategy, herein, ordered single-crystalline nanowire patterns and optoelectronic devices of a semiconducting molecular ferroelectric (SMF), hexane-1,6-diammonium pentaiodobismuth (HDA-BiI5), were successfully demonstrated. The coupling of semiconducting and ferroelectric polarization of the SMF devices enables a broadband self-powered photodetection from ultraviolet to visible light, as well as polarization-tunable photoresponsivity. These may open an avenue for high-performance SMF optoelectronic memory devices with low cost and flexibility.

Self-Powered Deep-Ultraviolet Photodetector Driven by Combined Piezoelectric/Ferroelectric Effects

In this study, in situ piezoelectricity was incorporated into the photoactive region to prepare a self-powered deep-ultraviolet photodetector based on a mixture of polyvinylidene fluoride (PVDF)@Ga2O3 and polyethyleneimine (PEI)/carbon quantum dots (CQDs). A ferroelectric composite layer was prepared using β-Ga2O3 as a filler, and the β-phase of PVDF was used as the polymer matrix. The strong piezoelectricity of β-PVDF can facilitate the separation and transport of photogenerated carriers in the depletion region and significantly reduce the dark current when the device is biased with an external bias, resulting in a high on/off ratio and high detection capability. The self-powered PD exhibited specific detectivity (D* = 3.5 × 1010 Jones), an on/off ratio of 2.7, and a response speed of 0.11/0.33 s. Furthermore, the prepared PD exhibits excellent photoresponse stability under continuous UV light, with the photocurrent retaining 83% of its initial value after about 500 s of irradiation. Our findings suggest a new approach for developing cost-effective UV PDs for optoelectronic applications in related fields.

Photocurrent and electrical properties of SiGe nanocrystals grown on insulator via solid-state dewetting of Ge/SOI for Photodetection and solar cells applications

In this study, we present the photocurrent and electrical characterization of silicon-germanium nanocrystals (SiGe NCs) on an insulator (SiO2). The SiGe NCs were grown through a hybrid process combining solid-phase dewetting of an ultra-thin silicon-on-insulator (UT-SOI) film with the epitaxial deposition of a thin germanium layer using ultra-high vacuum molecular beam epitaxy (UHV-MBE). These SiGe NCs were successfully integrated into the insulator layer of a metal-insulator-semiconductor (MIS) structure for optoelectronic applications. The enhanced MIS structure, featuring integrated SiGe NCs, exhibited notable transport and optoelectric properties as determined by current-voltage and impedance spectroscopy. The results indicated that the MIS structure functions as a Schottky diode, demonstrating a high rectification ratio (RR) of approximately 1000 and a Schottky barrier height (ϕB) of 0.73 eV. Additionally, this structure displayed a broad spectral response in the visible range, with a significant photovoltaic effect. The equivalent circuit of the MIS structure was also derived for an AC signal using impedance spectroscopy. These findings offer a promising scalable method for the monolithic integration and efficient growth of SiGe nanocrystals, paving the way for advancements in self-powered photodetectors and ultrathin solar cells.

A general strategy for enhancing the performance of Ga2O3-based self-powered solar-blind photodetectors through band structure engineering

Abstract The spectral response of Ga2O3 almost perfectly covers the 200~280 nm solar-blind ultraviolet wavelength range, making it an ideal semiconductor material for fabricating solar-blind ultraviolet photodetectors. However, due to the considerably deep valence band energy of Ga2O3 the construction of heterojunctions typically induces a significant valence band offset (EV). Herein, we present a band engineering approach to improve the performance of Ga2O3 bases photodetectors. This pronounced valence band barrier can strongly influence the transport of photo-generated charge carriers, especially the extraction of holes in the depletion region. By introducing nitrogen (N) during the growth process, we elevated the valence band of Ga2O3 by 0.43 eV. The organic high-molecular-weight material of PEDOT:PSS has been utilized in conjunction with Ga2O3 to construct heterojunction photodetectors. The photodetectors exhibit excellent self-powered characteristics, with responsivity, detectivity, and response time being nearly ten times higher than those of Ga2O3 photodetectors before band structure modulation. The investigation into modulating the band structure of Ga2O3 carried out in this study will lay the theoretical foundation and provide technical solutions for developing satisfactory self-powered photodetectors.

High-Efficiency Self-Powered Photodetector for UV-Visible-NIR Spectrum Using Solution-Processed TiO2/Cu2ZnSnS4 Heterojunction in Superstrate Configuration

This study introduces a sustainable and efficient approach for self-powered photodetection using a solution-processed TiO2/CZTS heterojunction to detect the broad electromagnetic spectrum. CZTS thin films with a pure kesterite phase are synthesized via a cost-effective sol-gel spin coating technique, eliminating the need for high-temperature post-deposition sulfurization. The formation of the kesterite phase in CZTS films is confirmed through microstructural studies, Raman spectroscopy, and optical analyses. A high-quality heterojunction is fabricated by depositing the CZTS layer on chemically synthesized TiO2 thin film on FTO-coated glass substrates, and its photoresponse characteristics are studied under 365nm, 405nm, 532nm, 650nm, and 980nm light in a superstrate configuration. The heterojunction exhibits optimal photoresponsivity (~1.28mA/W), detectivity (~4.77 ×10¹⁰ Jones), and rise/decay times (~54 ms/27 ms) at zero external bias. It also demonstrates efficient performance under 1 sun AM1.5G solar spectrum. The photodetection mechanism through carrier dynamics under illumination for the heterostructure is further investigated using impedance spectroscopy, incident light-dependent capacitance-voltage characteristics, and photo-capacitance measurements. This approach provides a cost-effective and scalable solution for self-powered photodetection, offering significant potential for integration into various optoelectronic devices for renewable energy harvesting and sensing applications.

Large-scale free-standing Bi2Te3/Si heterostructures developed by a modified solvothermal method for a self-powered and efficient imaging photodetector

Topological insulator bismuth telluride (Bi2Te3), an exotic state of quantum matter, has broad application prospects in next-generation optoelectronic devices. However, photoexcited carriers in Bi2Te3 usually relax rapidly due to the lack of a large band gap. Herein, high-quality Bi2Te3/Si heterojunction is successfully synthesized by a low-cost modified two-step solvothermal method to grow large-scale free-standing Bi2Te3 nanosheets on a Si substrate. Benefiting from the promotion of photogenerated carrier separation and transport by the built-in electric field at the Bi2Te3/Si heterojunction interface, the Bi2Te3/Si heterojunction photodetector exhibits a high responsivity of 16.44 mA W−1, a high specific detectivity of 2.44 × 1011 Jones, and fast rise/recovery times of 11/13 ms under 470 nm illumination at zero bias. Additionally, the device has potential applications in high-resolution imaging. In view of its overall photosensitivity performance and low cost, the Bi2Te3/Si heterojunction synthesized by the solvothermal method has a promising application in fast broadband photodetectors, and also provide a new route for the growth of Bi2Te3 nanosheets on substrates.

Cost-effective self-powered heterostructure π-SnS/Si photodetector with superior sensitivity for near-infrared light

Photodetectors generally require external power supplies to facilitate the separation of charge carriers and the generation of photocurrents. This significantly enlarges the device's dimensions and weight, limiting its applicability in real-time medical therapy monitoring and wireless environmental sensing. To address this limitation, extensive research focuses on developing self-powered photodetectors that operate autonomously without external power sources. The heterojunction structure photodetector, characterized by a sufficient built-in potential, facilitates the separation of photo charge carriers and the generation of photocurrent, leading to self-powered photodetectors. In this study, a novel and straightforward heterostructure photodetector was developed using a tin monosulfide (π-SnS) film and silicon (Si). This device exhibited a barrier height of 0.82 eV, which effectively separates photogenerated carriers and results in a highly sensitive (5.7 × 104) self-powered photodiode for near-infrared light. The SnS film was deposited onto an n-type Si wafer substrate using a simple and cost-effective chemical bath deposition method. The photoresponse characteristics were controlled and tuned by adjusting the operating bias voltage and illumination power density. At a bias voltage of 5 V, the photodiode demonstrated high responsivity (3863 mA/W) and detectivity (7.2 × 1011 Jones). The π-SnS/Si self-powered heterojunction photodetector, with its superior sensitivity, holds promise for advancing the technological implementation of optoelectronic devices.

Quasi-Single-Crystal Tin Halide Perovskite Films with High Structural Integrity for Near-Infrared Imaging Array Enabling Hidden Object Recognition.

Near-infrared (NIR) image sensors based on solution-processed thin film are gaining prominence in various applications, including security detection, remote sensing, medical imaging, and environmental monitoring, owing to superior penetration capabilities of NIR light. However, the reported perovskite image sensors suffer from limited resolution and performance due to poor structural integrity, bioincompatibility, and constrained response wavelength range from lead-based perovskite materials employed. In this study, we present non-toxic quasi-single-crystal (QSC) CH(NH2)2SnI3 (FASnI3) perovskite films, prepared via a simple spin-coating technique, that demonstrate high structural integrity and effective NIR response. Through a series of in situ characterizations, we reveal that the orderly growth mode of QSC-FASnI3 perovskite films enables a more oriented crystal growth with reduced trap and grain boundaries. Consequently, self-powered NIR photodetector based on QSC-FASnI3 films exhibited large detectivity over 1013 Jones in the NIR range (780-890 nm). Ultimately, due to the high structural integrity, the high-resolution 64×64 (4096) pixels NIR imaging array, exhibiting reduced photo and dark response non-uniformity value, was fabricated on the thin-film transistors (TFT) backplanes, enabling ultraweak NIR light (63 nW cm-2) real-time imaging, fingerprint imaging, and hidden object recognition. This work pioneers the application of lead-free perovskite for high-resolution NIR imaging arrays.

Vis-infrared wide-band and self-powered photodetectors base on CuI/MoS2 van der Waals heterostructure

The realization of self-powered and wide-band detection functions through a single photodetector is an important development direction for the next generation of photodetectors. Here, the CuI/MoS2 heterojunction photodetectors constructed by combining dry and wet transfer techniques has achieved self-powered and wide-band detection. Under 405 nm illumination, CuI/MoS2 heterojunction PDs achieved an open circuit voltage of 90mV and a short-circuit current of 4.869 nA, and in self-powered operation mode, the responsivity can reach 386 mA/W. In addition, within the testing wavelength range of 405 nm to 1010 nm, the responsivity of CuI/MoS2 heterojunction photodetectors is significantly better than that of a single MoS2 photodetectors, with a 3.35-fold boost in responsivity at the highest value. These results indicate that CuI/MoS2 heterojunction photodetectors have better wide-band response in the visible and near-infrared spectral ranges. Moreover, we have developed a signal recognition system to demonstrate the wide-band imaging capability of photodetectors. This work reveals the strong potential of CuI/MoS2 heterojunction photodetectors in the fields of self-powered and wide-band optoelectronic detection.

High-Performance Self-Powered Dual-Mode Ultraviolet Photodetector Based on (PEA)2PbI4/GaN Heterojunction.

Wide-bandgap semiconductors like GaN, known for their superior photoresponse and detection capabilities in the ultraviolet range, represent a foundational component in the design of advanced photodetectors, where the integration of materials with distinct spectral sensitivities into heterojunctions is pivotal for next-generation device innovation. A high-performance self-powered dual-mode ultraviolet photodetector based on a (PEA)2PbI4/GaN heterojunction was fabricated via spin coating. The device exhibits outstanding UV sensitivity under both positive and negative bias, achieving a responsivity of 1.39 A/W and a detectivity of 8.71 × 1010 Jones under 365 nm UV illumination. The built-in electric field at the heterojunction interface enables self-powered operation, achieving a rapid rise time of 46.9 ms and a decay time of 55.9 ms. These findings offer valuable insights into the development and application of perovskite and wide-bandgap semiconductor heterojunctions in optoelectronic devices.

Self-powered Sb2S3 photodetectors with efficient carrier transport enabled by compact vertical TiO2 nanorods.

Antimony sulfide (Sb2S3) photodetectors (PDs) possess extensive application prospects. Efficient carrier transport of a PD significantly affects the detectivity and response speed. Herein, we propose an all-inorganic self-powered Sb2S3 PD based on vertical TiO2 nanorods (NRs). The spray-coated 15-nm TiO2 thin film as a seed layer ensures the growth of compact vertical TiO2 nanorod arrays by the hydrothermal method. One-dimensional TiO2 nanorods facilitate photocarrier separation and transport to enhance device performance. Ultimately, the Sb2S3 PD achieves a responsivity of 0.29 A/W, a specific detectivity of 3.37 × 1012 Jones, and a response time of 7.8 µs, showing great potential in commercial applications.

Self-powered visible-blind ultraviolet photodetectors based on SnO2 nanowire cotton synthesized using thermal chemical vapor deposition

Self-powered visible-blind ultraviolet photodetectors based on SnO2 nanowire cotton synthesized using thermal chemical vapor deposition

Spraying-Deposited Transparent p-Type Sn-Doped CuI Film and Its Ultrahigh-Speed Self-Powered Photodetector.

The exploitation of simply processed p-type semiconductors and photodetectors with promising optoelectrical properties remains challenging yet essential for current and future advanced optoelectronic applications. Transparent p-type CuI and Sn-doped CuI (Cu-Sn-I) films and their self-powered photodetectors have been successfully fabricated by the spraying method. It is found that the incorporation of Sn dopants enhances the optical, electrical, and photoelectric properties of CuI thin films as well as their corresponding self-powered heterojunction photodetectors. This improvement of the optoelectrical properties of the Cu-Sn-I film and its photodetector can be attributed to the adjustment of the acceptor defect level and increased hole concentration resulting from Sn doping. The Cu-Sn-I/n-Si photodetector exhibits a responsivity of 10.7 mA/W, a detectivity of 6.79 × 1011 Jones, and a response time of 77 μs/30 μs (0 V bias). The response time exhibits the fastest rise and decay times compared with the other CuI-based self-powered UV photodetectors in recent years, showcasing promising applications in the realm of transparent electronics moving forward. This study also presents an effective strategy for enhancing the electrical properties of p-type semiconductors and devices through effective doping.

High-Performance Gate-Voltage-Tunable Photodiodes Based on Nb2Pd3Se8/WSe2 Mixed-Dimensional Heterojunctions.

The mixed-dimensional (MD) van der Waals (vdWs) heterojunction for photodetectors has garnered significant attention owing to its exceptional compatibility and superior quality. Low-dimensional material heterojunctions exhibit unique photoelectric properties attributed to their nanoscale thickness and vdWs contact surfaces. In this work, a novel MD vdWs heterojunction composed of one-dimensional (1D) Nb2Pd3Se8 nanowires and two-dimensional (2D) WSe2 nanosheets is proposed. The heterojunction's energy band engineering is accomplished by manipulating the Fermi level of the bipolar 2D material via gate voltage, resulting in a rectification characteristic that can be adjusted with gate voltage. Under 685 nm laser irradiation, it demonstrates exceptional self-powered photodetection performance, attaining a photoresponsivity of 1.45 A W-1, an ultrahigh detectivity of 6.8 × 1012 Jones, and an ultrafast response time of 37/64 μs at zero bias. In addition, a broadband photodetector from 255 to 1064 nm is realized. These results demonstrate the great potential of Nb2Pd3Se8/WSe2 MD heterostructures for advanced electronic and optoelectronic devices.

Edge-dependent photogalvanic effect in 1T′-ReS2-based polarization self-powered photodetectors

Polarization photodetectors with linear/circular photogalvanic effect (L/CPGE) have garnered significant attention due to their wide range of application prospects. However, few kinds of photodetectors are adept at distinguishing between LPGE and CPGE. Here, we investigated a type of polarization-sensitive photodetector based on 1T′-ReS2 nanoribbon (1T′-ReS2 NR) within the framework of density functional theory. It is found that the CPGE photocurrent of 1T′-ReS2 NR along the zigzag direction can be 102 to 103 times larger than that of LPGE. Moreover, the sensitivity to polarized light of 1T′-ReS2 NR can be significantly enhanced. The extinction ratio can be up to 55, which is 4.6 times higher than that the 1T′-ReS2 monolayer. Remarkably, the introduction of magnetism through edge effects enables 1T′-ReS2 NR photodetector to achieve a spin injection efficiency close to 100%. Our results provide an avenue for the design of high-photosensitivity and low-power spintronic devices.

Self-powered water-based graphene photodetector for extremely rapid detection of SARS-CoV-2

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a highly contagious virus, which has caused a serious public health crisis all over the world. Current coronavirus detection methods mainly rely on PCR technology, which needs high standard laboratory facilities and a long time to extract, react and analyze samples. In this report, a self-powered water-based photodetector (PD) biological detection device is designed to detect SARS-CoV-2 in the Dulbecco's Modified Eagle Medium (DMEM) solution. The graphene layer on top of liquid is covered with specific antibodies against SARS-CoV-2 spike protein. The device can detect SARS-CoV-2 exclusively with a concentration of 1 × 104 TCID50 in DMEM solution. It can push the detection limit down to 62 copies per μL with the detection time less than 100 ms. The work presents a rapid SARS-CoV-2 immunodiagnostic method without sample pretreatment or labeling.