Highly Diffusive Nonluminescent Carriers in Hybrid Phase Lead Triiodide Perovskite Nanowires.

Crystal structural rearrangements unavoidably introduce defects into materials, where even these small changes in local lattice structure could arouse a prominent impact on the overall nature of crystals. Contrary to the traditional notion that defects obstruct carrier transport, herein, we report a promoted transport mechanism of nonluminescent carriers in single-crystalline CH3NH3PbI3 nanowires (1345.2 cm2 V-1 s-1, about a 14-fold improvement), enabled by the phase transition induced defects (PTIDs). Carriers captured by PTIDs evade both the radiative and non-radiative recombinations during the incomplete tetragonal-to-orthorhombic phase transition at low temperatures, forming a specific nonluminescent state that exhibits an efficient long-distance transport and thereby realize a prominent enhancement of photocurrent responsivity for photodetector applications. The findings provide broader insights into the carrier transport mechanism in perovskite semiconductors and have significant implications for their rational design for photoelectronic applications at varied operating temperatures.

Transferrable CsPbBr3 Perovskite Single-Crystalline Films for Visible-Wavelength Photodetectors.

In this study, we propose large-scale CsPbBr3 (CPB) single-crystalline films (SCFs) grown by a one-step vapor-phase epitaxy (VPE) method for application in optoelectronic devices. After optimizing the transport speed of the precursor and cooling rate, we obtained continuous CPB films with a lateral size exceeding 2 cm2, and the thickness could be controlled from several micrometers to hundreds of nanometers. Crystallography and optoelectronic characterization proved the excellent crystallinity and very low trap density (2.14 × 1011) of the SCFs. Furthermore, we demonstrate a transfer-assembly strategy for fabricating perovskite SCF-based heterostructures for visible photodetectors. The high-quality SCF films in the active layer suppress the leakage current, leading to a low dark current of 5 × 10-10 A at -0.6 V. Therefore, the self-biased photodetector based on the vertical CsPbBr3 SCF-SnO2 heterostructure showed a high responsivity of 1.9 A/W, a detectivity of 4.65 × 1012 Jones, and a large on/off ratio of 4.63 × 103 under a 1 mW/cm2 450 nm light illumination. Our study not only demonstrates the excellent performance of single-crystalline perovskite-based photodiodes but also provides a universal assembly method for the integration of monocrystalline perovskite films in optoelectronic devices.

Sensitive SWIR Organic Photodetectors with Spectral Response Reaching 1.5 µm.

The performance of organic photodetectors (OPDs) sensitive to the short-wavelength infrared (SWIR) light lags behind commercial indium gallium arsenide (InGaAs) photodetectors primarily due to the scarcity of organic semiconductors with efficient photoelectric responses exceeding 1.3 µm. Limited by the Energy-gap law, ultralow-bandgap organic semiconductors usually suffer from severe non-radiative transitions, resulting in low external quantum efficiency (EQE). Herein, a difluoro-substituted quinoid terminal group (QC-2F) with exceptionally strong electron-negativity is developed for constructing a new non-fullerene acceptor (NFA), Y-QC4F with an ultralow bandgap of 0.83 eV. This subtle structural modification significantly enhances intermolecular packing order and density, enabling an absorption onset up to 1.5 µm while suppressing non-radiation recombination in Y-QC4F films. SWIR OPDs based on Y-QC4F achieve an impressive detectivity (D*) over 1011 Jones from 0.4 to 1.5 µm under 0 V bias, with a maximum of 1.68 × 1012 Jones at 1.16 µm. Furthermore, the resulting OPDs demonstrate competitive performance with commercial photodetectors for high-quality SWIR imaging even under 1.4 µm irradiation.

Development of Self-Doped Monolayered 2D MoS2 for Enhanced Photoresponsivity.

Transition metal dichalcogenides (TMDs) exist in two distinct phases: the thermodynamically stable trigonal prismatic (2H) and the metastable octahedral (1T) phase. Phase engineering has emerged as a potent technique for enhancing the performance of TMDs in optoelectronics applications. Nevertheless, understanding the mechanism of phase transition in TMDs and achieving large-area synthesis of phase-controlled TMDs continue to pose significant challenges. This study presents the synthesis of large-area monolayered 2H-MoS2 and mixed-phase 1T/2H-MoS2 by controlling the growth temperature in the chemical vapor deposition (CVD) method without use of a catalyst. The field-effect transistors (FETs) devices fabricated with 1T/2H-MoS2 mixed-phase show an on/off ratio of 107. Photo response devices fabricated with 1T/2H-MoS2 mixed-phase show ≈55 times enhancement in responsivity (from 0.32 to 17.4 A W-1) and 102 times increase in the detectivity (from 4.1 × 1010 to 2.48 × 1012 cm Hz W-1) compare to 2H-MoS2. Introducing the metallic 1T phase within the 2H phase contributes additional carriers to the material, which prevents the electron-hole recombination and thereby increases the carrier density in the 1T/2H-MoS2 mixed-phase in comparison to 2H-MoS2. This work provides insights into the self-doping effects of 1T phase in 2H MoS2, enabling the tuning of 2D TMDs properties for optoelectronic applications.

Composition Modulation-Mediated Band Alignment Engineering from Type I to Type III in 2D vdW Heterostructures.

Band alignment engineering is crucial for facilitating charge separation and transfer in optoelectronic devices, which ultimately dictates the behavior of Van der Waals heterostructures (vdWH)-based photodetectors and light emitting diode (LEDs). However, the impact of the band offset in vdWHs on important figures of merit in optoelectronic devices has not yet been systematically analyzed. Herein, the regulation of band alignment in WSe2/Bi2Te3- xSex vdWHs (0 ≤ x ≤ 3) is demonstrated through the implementation of chemical vapor deposition (CVD). A combination of experimental and theoretical results proved that the synthesized vdWHs can be gradually tuned from Type I (WSe2/Bi2Te3) to Type III (WSe2/Bi2Se3). As the band alignment changes from Type I to Type III, a remarkable responsivity of 58.12 A W-1 and detectivity of 2.91×1012 Jones (in Type I) decrease in the vdWHs-based photodetector, and the ultrafast photoresponse time is 3.2 µs (in Type III). Additionally, Type III vdWH-based LEDs exhibit the highest luminance and electroluminescence (EL) external quantum efficiencies (EQE) among p-n diodes based on Transition Metal Dichalcogenides (TMDs) at room temperature, which is attributed to band alignment-induced distinct interfacial charge injection. This work serves as a valuable reference for the application and expansion of fundamental band alignment principles in the design and fabrication of future optoelectronic devices.

The Influence of Electrolytes on the Performance of Self-Powered Photoelectrochemical Photodetector Based on α-Ga2O3 Nanorods.

Photodetectors have a wide range of applications across various fields. Self-powered photodetectors that do not require external energy have garnered significant attention. The photoelectrochemical type of photodetector is a self-powered device that is both simple to fabricate and offers high performance. However, developing photoelectrochemical photodetectors with superior quality and performance remains a significant challenge. The electrolyte, which is a key component in these detectors, must maintain extensive contact with the semiconductor without degrading its material quality and efficiently catalyze the redox reactions of photogenerated electrons and holes, while also facilitating rapid charge carrier transport. In this study, α-Ga2O3 nanorod arrays were synthesized via a cost-effective hydrothermal method to achieve a self-powered solar-blind photodetector. The impacts of different electrolytes-Na2SO4, NaOH, and Na2CO3-on the photodetector was investigated. Ultimately, a self-powered photodetector with Na2SO4 as the electrolyte demonstrated a stable photoresponse, with the maximum responsivity of 0.2 mA/W at 262 nm with the light intensity of 3.0 mW/cm2, and it exhibited rise and decay times of 0.16 s and 0.10 s, respectively. The α-Ga2O3 nanorod arrays and Na2SO4 electrolyte provided a rapid pathway for the transport of photogenerated carriers and the built-in electric field at the semiconductor-liquid heterojunction interface, which was largely responsible for the effective separation of photogenerated electron-hole pairs that provided the outstanding performance of our photodetector.

Silicon Waveguide-Integrated Platinum Telluride Midinfrared Photodetector with High Responsivity and High Speed.

The detection of mid-infrared light, covering a variety of molecular vibrational spectra, is critical for both civil and military purposes. Recent studies have highlighted the potential of two-dimensional topological semimetals for mid-infrared detection due to their advantages, including van der Waals (vdW) stacking and gapless electronic structures. Among them, mid-infrared photodetectors based on type-II Dirac semimetals have been less studied. In this paper, we present a silicon waveguide integrated type-II Dirac semimetal platinum telluride (PtTe2) mid-infrared photodetector, and further improve detection performance by using PtTe2-graphene heterostructure. For the fabricated silicon waveguide-integrated PtTe2 photodetector, with an external bias voltage of -10 mV and an input optical power of 86 nW, the measured responsivity is 2.7 A/W at 2004 nm and a 3 dB bandwidth of 0.6 MHz is realized. For the fabricated silicon waveguide-integrated PtTe2-graphene photodetector, as the external bias voltage and input optical power are 0.5 V and 0.13 µW, a responsivity of 5.5 A/W at 2004 nm and a 3 dB bandwidth of 35 MHz are obtained. An external quantum efficiency of 119% can be achieved at an input optical power of 0.376 µW.

Vapor Growth of All-Inorganic 2D Ruddlesden-Popper Lead- and Tin-Based Perovskites.

The 2D Ruddlesden-Popper (RP) perovskites Cs2PbI2Cl2 (Pb-based, n = 1) and Cs2SnI2Cl2 (Sn-based, n = 1) stand out as unique and rare instances of entirely inorganic constituents within the more expansive category of organic/inorganic 2D perovskites. These materials have recently garnered significant attention for their strong UV-light responsiveness, exceptional thermal stability, and theoretically predicted ultrahigh carrier mobility. In this study, we synthesized Pb and Sn-based n = 1 2D RP perovskite films covering millimeter-scale areas for the first time, utilizing a one-step chemical vapor deposition (CVD) method under atmospheric conditions. These films feature perovskite layers oriented horizontally relative to the substrate. Multilayered Cs3Pb2I3Cl4 (Pb-based, n = 2) and Cs3Sn2I3Cl4 (Sn-based, n = 2) films were also obtained for the first time, and their crystallographic structures were refined by combining X-ray diffraction (XRD) and density functional theory (DFT) calculations. DFT calculations and experimental optical spectroscopy support band-gap energy shifts related to the perovskite layer thickness. We demonstrate bias-free photodetectors using the Sn-based, n = 1 perovskite with reproducible photocurrent and a fast 84 ms response time. The present work not only demonstrates the growth of high-quality all-inorganic multilayered 2D perovskites via the CVD method but also suggests their potential as promising candidates for future optoelectronic applications.

A Photolithography-Free Fabrication Strategy for Perovskite Photodetector Array with High-Security Imaging Application.

Metal halide perovskites have attracted significant attention for high-performance and cost-effective photodetector (PD) arrays in recent years. Traditional perovskite photodetector arrays typically rely on planar structure and photolithography, which limit resolution and involve complex, costly processes. To address these challenges, an innovative, lithography-free fabrication strategy is proposed utilizing direct laser writing ablation and a surface energy-assisted selective growth process. A 10 × 10 self-powered perovskite photodetector array is demonstrated with a vertical cross-bar structure fabricated on a laser-ablated textured Indium-Tin Oxide (ITO) substrate which improves the device performance. The device exhibits a fast photoresponse and effective imaging capability. Moreover, the intrinsic physical disorder and randomness of perovskite provide highly secure entropy sources, making the photodetector array suitable for physical unclonable function (PUF) devices. This method offers a promising opportunity for simplifying the fabrication process, enhancing manufacturability, and advancing the application of perovskite PD arrays in secure imaging systems.

Design of Ultra-Narrow Bandgap Polymer Acceptors for High-Sensitivity Flexible All-Polymer Short-Wavelength Infrared Photodetectors.

All-polymer photodetectors possess unique mechanical flexibility and are ideally suitable for the application in next-generation flexible, wearable short-wavelength infrared (SWIR, 1000-2700 nm) photodetectors. However, all-polymer photodetectors commonly suffer from low sensitivity, high noise, and low photoresponse speed in the SWIR region, which significantly diminish their application potential in wearable electronics. Herein, two polymer acceptors with absorption beyond 1000 nm, namely P4TOC-DCBT and P4TOC-DCBSe, were designed and synthesized. The two polymers possess rigid structure and good conformational stability, which is beneficial for reducing energetic disorder and suppressing dark current. Owing to the efficient charge generation and ultralow noise current, the P4TOC-DCBT-based all-polymer photodetector achieved a specific detectivity () of over 1012 Jones from 650 (visible) to 1070 nm (SWIR) under zero bias, with a response time of 1.36 µs. These are the best results for reported all-polymer SWIR photodetectors in photovoltaic mode. More significantly, the all-polymer blend films exhibit good mechanical durability, and hence the P4TOC-DCBT-based flexible all-polymer photodetectors show a small performance attenuation (<4%) after 2000 cycles of bending to a 3 mm radius. The all-polymer flexible SWIR organic photodetectors  are successfully applied in pulse signal detection, optical communication and image capture.

Enhanced Thermal Stability of Conductive Mercury Telluride Colloidal Quantum Dot Thin Films Using Atomic Layer Deposition.

Colloidal quantum dots (CQDs) are valuable for their potential applications in optoelectronic devices. However, they are susceptible to thermal degradation during processing and while in use. Mitigating thermally induced sintering, which leads to absorption spectrum broadening and undesirable changes to thin film electrical properties, is necessary for the reliable design and manufacture of CQD-based optoelectronics. Here, low-temperature metal-oxide atomic layer deposition (ALD) was investigated as a method for mitigating sintering while preserving the optoelectronic properties of mercury telluride (HgTe) CQD films. ALD-coated films are subjected to temperatures up to 160 °C for up to 5 h and alumina (Al2O3) is found to be most effective at preserving the optical properties, demonstrating the feasibility of metal-oxide in-filling to protect against sintering. HgTe CQD film electrical properties were investigated before and after alumina ALD in-filling, which was found to increase the p-type doping and hole mobility of the films. The magnitude of these effects depended on the conditions used to prepare the HgTe CQDs. With further investigation into the interaction effects of CQD and ALD process factors, these results may be used to guide the design of CQD-ALD materials for their practical integration into useful optoelectronic devices.

High-Speed Self-Powered PdSe2/Si 2D-3D PIN-like Photodetector with Broadband Response Based on PdSe2 Quantum Island Structure.

As a two-dimensional (2D) material, palladium diselenide (PdSe2) has attracted extensive research attention due to its unique asymmetric crystal structure and extraordinary optoelectronic properties, showing great potential in electronic, optoelectronic, and other application fields. Thinner PdSe2 exhibits semiconductor properties, while the photoresponse of the photodetectors based on this film is weaker. Although increasing the thickness of the PdSe2 film can improve the photoresponse, thicker PdSe2 exhibits metallic-like properties, which is not conducive to the formation of the heterojunction. In this work, a PdSe2 2D material with a quantum island structure is prepared by a simple thermal-assisted conversion method. A new type of photodetector with a PdSe2/n--Si/n+-Si vertical PIN-like structure is innovatively proposed. Broad spectral absorption from 532 to 2200 nm and a high rectification ratio (106) of the device are achieved. The introduced n--Si layer concentrates the electric field in the depletion region, thereby shortening the transit time and accelerating the separation and collection of the carriers, resulting in the enhancement of the responsivity and 3 dB frequency compared to the traditional device with a PN structure. A recorded highest 3 dB frequency of ∼25 kHz is achieved for the PdSe2 2D-3D PIN-like device.

Self-Powered FTO/CdSe/Bi2Se3 Photodetector with Bipolar Photoresponse Characteristics.

Self-powered photodetectors with bipolar photoresponse characteristics are expected to play a critical role in the field of secure optical communication, artificial neuromorphic systems, and intelligent color sensors. In this work, asymmetric heterojunction devices exhibiting wavelength-dependent bipolar photoresponse with a structure of Glass/FTO/CdSe/Bi2Se3/Au were fabricated. Under a short wavelength light irradiation, the top CdSe absorber generates a high carrier concentration; the excited carriers are quickly separated by the built-in electric field induced by the FTO/CdSe diode, resulting in a negative photocurrent. For light with wavelengths beyond the CdSe absorption edge, it is absorbed by the bottom Bi2Se3 absorber, and a positive photocurrent can be observed. Therefore, based on the bandgap difference between the top CdSe absorber and the bottom Bi2Se3 absorber, combined with the photogenerated carriers separated by asymmetric back-to-back diode, a wavelength-dependent bipolar response is realized. In this work, by employing this structure, the responsivities of -33.3 and 0.3 mA/W were achieved under the illumination of 405 and 830 nm, respectively. This work provides important indications in the preparation and performance optimization for wavelength-dependent bipolar photodetectors.

Visible-light Photodetection by Zero-Dimensional Hybrid Indium-Halide with Minimal Structural Distortion and Reduced Band Gap.

Perovskite-inspired zero-dimensional (0D) hybrid halides exhibit impressive light emission properties; however, their potential in photovoltaics is hindered by the absence of interconnection between the inorganic polyhedra, leading to acute radiative recombination and insufficient charge separation. We demonstrate that incorporating closely-spaced dissimilar polyhedral units with minimal structural distortion leads to a remarkable enhancement in visible-light photodetection capability. We designed 0D C24H72N8In2Br14 (HIB) with a tetragonal crystal system, replacing the Cs+ of Cs2InBr5.H2O (CIB) with 1,6-hexanediammonium (HDA) cation. HIB comprises [InBr6]3- octahedra, and [InBr4]- tetrahedra units spaced 3.9 Å apart by the HDA linker. The [InBr4]- unit is additionally linked to HDA via intercalated bromine through hydrogen and halogen bonding interactions, respectively. This structural arrangement lowers the dielectric confinement, thereby enhancing carrier density and mobility, and increasing the diffusion coefficient compared to CIB. With 3.6% bromine vacancy within the [InBr4]- block, mid-gap states are created, reducing the direct band gap to 2.19 eV. HIB demonstrates an unprecedently high responsivity of 9975.9 ± 201.6 mA W-1 under 3 V potential bias at 485 nm wavelength, among low-dimensional hybrid halides. In the absence of potential bias, the self-powered photodetection parameters are 81.2 ± 3.0 mA W-1 and (6.98 ± 0.21) × 109 Jones.

Synergic Surface Modifications of PbS Quantum Dots by Sodium Acetate in Solid-State Ligand Exchange toward Short-Wave Infrared Photodetectors.

PbS quantum dots (QDs) are promising for short-wave infrared (SWIR) photodetection and imaging. Solid-state ligand exchange (SSLE) is a low-fabrication-threshold QD solid fabrication method. However, QD treatment by SSLE remains challenging in seeking refined surface passivation to achieve the desired device performance. This work investigates using NaAc in the ligand exchange process to enhance the film morphology and electronic coupling configuration of QD solids. By implementing various film and photodetector device characterization studies, we confirm that adding NaAc with a prominent adding ratio of 20 wt % NaAc with tetrabutylammonium iodide (TBAI) in the SSLE leads to an improved film morphology, reduced surface roughness, and decreased trap states in the QD solid films. Moreover, compared to the devices without NaAc treatment, those fabricated with NaAc-treated QD solids exhibit an enhanced performance, including lower dark current density (<100 nA/cm2), faster response speed, higher responsivity, detectivity, and external quantum efficiency (EQE reaching 25%). The discoveries can be insightful in developing efficient, low-cost, and low-fabrication-threshold QD SWIR detection and imager applications.

Light-Adapted Optoelectronic-Memristive Device for the Artificial Visual System.

With the development of artificial intelligence systems, it is necessary to develop optoelectronic devices with photoresponse and storage capacity to simulate human visual perception systems. The key to an artificial visual perception system is to integrate components with both sensing and storage capabilities of illumination information. Although module integration components have made useful progress, they still face challenges such as multispectral response and high energy consumption. Here, we developed a light-adapted optoelectronic-memristive device integrated by an organic photodetector and ferroelectric-based memristor to simulate human visual perception. ITO/P3HT:PC71BM/Au as the light sensor unit shows a high on/off ratio (Iph/Id) reaching ∼5 × 104 at 0 V. The memristor unit, consisting of ITO/CBI@P(VDF-TrFE)/Cu, has a RON/ROFF ratio window of ∼106 under 0.05 V read voltage and ultralow power consumption of ∼1 pW. Moreover, the artificial visual perception unit shows stable light-adapted memory windows under different wavelengths of irradiation light (400, 500, and 600 nm; they meet the spectral range of human visual recognition) and can clearly identify the target image ("T" shape) because of the apparent contrast, which results from the high ROFF/RON ratio values. These results provide a potential design strategy for the development of intelligent artificial vision systems.

Flexo-Phototronic Boosted Self-Powered Ultraviolet Detection in ZnAl:Layered Double Hydroxide Nanosheets/NiO Heterostructure.

Developing self-powered and flexible optoelectronic sensors with high responsivity and speed is crucial for modern applications, motivating continuous efforts to enhance their performance. Flexo-phototronics is a less-explored but promising technique to elevate the performance of optoelectronics. Therefore, this work addresses the potential of utilizing the flexo-phototronic effect to enhance the performance of a flexible and self-powered ultraviolet photodetector (UV PD) based on ZnAl:LDH (layered double hydroxides) nanosheets (Ns)/NiO heterostructure. The vertically oriented ZnAl:LDH Ns are synthesized via a simple method involving the immersion of a sputtered 10% Al-doped ZnO thin film in deionized water at room ambient conditions. The fabricated PD exhibits an impressive response to 365 nm UV light, with high sensitivity in the order of 103. The device's photocurrent and responsivity are significantly enhanced by the flexo-phototronic effect, attributed to the flexoelectric properties of ZnAl:LDH Ns. Specifically, applying an inhomogeneous tensile strain of 2% boosted the device responsivity by 57.1% and improved its operational speed. Furthermore, a working model revealing the altered energy-band structure is demonstrated to elucidate the flexo-phototronic-induced boost in the photoresponse. The PD also demonstrated a sustainable performance under severe bending cycles, underlining the good flexibility of the device. The results presented in this study demonstrate a self-powered and flexible UV PD and provide a viable approach to augment the performance of optoelectronics through the flexo-phototronic effect.

Vertical Barrier Heterostructures for Reliable and High-Performance Self-Powered Infrared Detection.

With their fascinating properties, emerging two-dimensional (2D) materials offer innovative ways to prepare high-performance infrared (IR) detectors. However, the current performance of 2D IR photodetectors is still below the requirements for practical application owing to the severe interfacial recombination, sharply raised contact resistance, and deteriorated metal conductivity at nanoscale. Here, we introduce a vertical barrier heterojunction with a structure of PtSe2/GaAs that combines the excellent optoelectronic properties of transition metal sulfides with topological semi-metals, which allows for an adjustable bandgap and high carrier mobility. The heterojunction was fabricated using the wet transfer method. The heterostructures show significant rectification behaviors and photovoltaic effects, which allow it to operate as a self-driven photodetector at zero bias. The photoresponse parameters at 850 nm with zero bias voltage are 67.2 mA W-1, 6.7 × 1012 Jones, 9.8%, 3.8 × 105, 164 µs, and 198 µs for the responsivity, specific detectivity, external quantum efficiency, Ilight/Idark ratio, rise time, and fall time, respectively. Moreover, the heterojunction is highly sensitive to a wide spectral band from ultraviolet to near-infrared (360-1550 nm). At the same time, this heterostructure demonstrates significant potential for applications in IR polarized light detection and room-temperature high-resolution IR imaging. The excellent properties of the heterojunction make it well-suited for high-performance, self-powered IR detection.

Interfacial Engineering for Controlled Crystal Mosaicity in Single-Crystalline Perovskite Films.

Organic-inorganic hybrid perovskites have attracted significant attention for optoelectronic applications due to their efficient photoconversion properties. However, grain boundaries and irregular crystal orientations in polycrystalline films remain issues. This study presents a method for producing crystalline-orientation-controlled perovskite single-crystal films using retarded solvent evaporation. It is shown that single-crystal films, grown via inverse temperature crystallization within a confined space, exhibit enhanced optoelectronic property. Using interfacial polymer layer, this method produces high-quality perovskite single-crystalline films with varying crystal orientations. Density functional theory calculations confirm favorable adsorption energies for (110) surfaces with methylammonium iodide and PbI2 terminations on poly(3-hexylthiophene), and stronger adsorption for (224) surfaces with I and methylammonium terminations on polystyrene, influenced by repulsive forces between the thiophene group and the perovskite surface. The correlation between charge transport characteristics and perovskite single-crystalline properties highlights potential advancements in perovskite optoelectronics, improving device performance and reliability.

WS2 Nanotube Transistor for Photodetection and Optoelectronic Memory Applications.

Nanotube and nanowire transistors hold great promises for future electronic and optoelectronic devices owing to their downscaling possibilities. In this work, a single multi-walled tungsten disulfide (WS2) nanotube is utilized as the channel of a back-gated field-effect transistor. The device exhibits a p-type behavior in ambient conditions, with a hole mobility µp ≈  1.4 cm2V-1s-1 and a subthreshold swing SS ≈ 10 V dec-1. Current-voltage characterization at different temperatures reveals that the device presents two slightly different asymmetric Schottky barriers at drain and source contacts. Self-powered photoconduction driven by the photovoltaic effect is demonstrated, and a photoresponsivity R ≈ 10 mAW-1 at 2 V drain bias and room temperature. Moreover, the transistor is tested for data storage applications. A two-state memory is reported, where positive and negative gate pulses drive the switching between two different current states, separated by a window of 130%. Finally, gate and light pulses are combined to demonstrate an optoelectronic memory with four well-separated states. The results herein presented are promising for data storage, Boolean logic, and neural network applications.