High-performance Broadband Photodetectors Research Articles

High-performance flexible and broadband photodetectors on paper substrates using FeSnS bimetallic sulfide nanosheets

Advancements in technology have made it easier to construct flexible broadband photodetectors for wearable devices, improving light harvesting and detecting capabilities. This work described a new study that used bimetallic sulfide nanosheets (FeSnS) to produce flexible and broadband photodetectors on paper substrates using hand-print method. A simple, economical, one-step hydrothermal technique was employed to synthesise FeSnS materials, which were characterised using XRD, UV–Vis Spectroscopy, FESEM, EDS, XPS, and UPS. Photodetection tests found that 2-FeSnS (Fe at 2 wt%) outperformed similar work on paper-based devices, with a responsivity of 32.4 mA/W under a 470 nm incident wavelength, high specific detectivity, and a response time of 1.16 s. Durability and flexibility testing validated the robustness of the device. The use of a simple hydrothermal synthesis and hand-print fabrication method to create high-performance, eco-friendly, and flexible photodetectors is novel, expanding their potential applications in wearable electronics, environmental monitoring, and low-cost disposable sensing platforms.

Highly DUV to NIR-II responsive broadband quantum dots heterojunction photodetectors by integrating quantum cutting luminescent concentrators

Low-cost, high-performance, and uncooled broadband photodetectors (PDs) have potential applications in optical communication etc., but it still remains a huge challenge to realize deep UV (DUV) to the second near-infrared (NIR-II) detection for a single broadband PD. Herein, a single PD affording broadband spectral response from 200 to 1700 nm is achieved with a vertical configuration based on quantum dots (QDs) heterojunction and quantum cutting luminescent concentrators (QC–LC). A broadband quantum dots heterojunction as absorption layer was designed by integrating CsPbI3:Ho3+ perovskite quantum dots (PQDs) and PbS QDs to realize the spectral response from 400 to 1700 nm. The QC–LC by employing CsPbCl3:Cr3+, Ce3+, Yb3+, Er3+ PQDs as luminescent conversion layer to collect and concentrate photon energy for boosting the DUV–UV (200–400 nm) photons response of PDs by waveguide effect. Such broadband PD displays good stability, and outstanding sensitivity with the detectivity of 3.19 × 1012 Jones at 260 nm, 1.05 × 1013 Jones at 460 nm and 2.23 × 1012 Jones at 1550 nm, respectively. The findings provide a new strategy to construct broadband detector, offering more opportunities in future optoelectronic devices.

Large area, ultrafast, suppressed dark current and high-performance PtSe2/MoS2 van der Waals heterostructure based visible to NIR broadband photodetector

Group-10 transitional metal dichalcogenide, in particular Platinum selenide (PtSe2), have attracted substantial attention owing to its fascinating properties such as high carrier mobility, narrow bandgap, and high stability in contrast to other low bandgap 2D materials. However, in bare PtSe2, high dark current and lower sensitivity restrict to make high-performance broadband photodetector. Herein, a large area and stable PtSe2/MoS2 heterostructure based photodetector is fabricated which exhibits suppressed dark current and high-performance with broad 400-1200 nm detection, covering visible to near-infrared region (NIR). The PtSe2/MoS2 heterostructure device exhibits ∼103 order reduction in the dark current, high detectivity, and better stable response as compared to its bare PtSe2 device. Moreover, under NIR (900 nm) illumination, the PtSe2/MoS2 device demonstrates high responsivity of 17.9 AW−1 and high specific detectivity of 9.8 × 1012 Jones at amoderate bias of −5V. It exhibits ultra-fast response with rise/ fall time of 103 μs/117 μs corroborating its high performance. To understand the working of PtSe2/MoS2 photodetector, a detailed carrier transport mechanism is investigated based on the interface. This work provides a facile strategy to fabricate large area, fast response and high-performance broadband photodetector to build future optoelectronic devices.

Oxidation-induced graded bandgap narrowing in Two-dimensional tin sulfide for high-sensitivity broadband photodetection

Two-dimensional (2D) layered group-IV monochalcogenides with large surface-to-volume ratio and high surface activity make that their structural and optoelectronic properties are sensitive to air oxidation. Here, we report the utilization of oxidation-induced gradient doping to modulate electronic structures and optoelectronic properties of 2D group-IV monochalcogenides by using SnS nanoplates grown by physical vapor deposition as a model system. By a precise control of oxidation time and temperature, the structural transition from SnS to SnSOx could be driven by the layer-by-layer oxygen doping and intercalation. The resulting SnSOx with a graded narrowing bandgap exhibits the enhanced optical absorption and photocurrent, leading to the fabricated SnSOx photodetector with remarkable photoresponsivity and fast response speed (<64 μs) at a broadband spectrum range of 520–1550 nm. The peak responsivity (7294 A/W) and detectivity (9.54 × 109 Jones) of SnSOx device are at least two orders of magnitude larger than those of SnS photodetector. Moreover, its photodetection performance can be competed with state-of-the-art of 2D materials-based photodetectors. This work suggests that the air oxidation could be utilized as an efficient strategy to engineer the electronic and optical properties of SnS and other 2D group-IV monochalcogenides for the development of high-performance broadband photodetectors.

Graphene electrode-enhanced InSe/WSe2 van der Waals heterostructure for high-performance broadband photodetector with imaging capabilities

2D vdWs heterostructure is realized as a powerful technique for tuning the optoelectronic properties and thus developing the future generation optoelectronic devices, especially for photodetectors. However, photodetectors based on 2D vdWs heterostructure suffer from responsivity, detectivity, and large photoresponse speed inhibits their applications in further diverse areas. Here, a graphene electrode-based InSe/WSe2 vdWs heterostructure is proposed aiming to develop a high-performance photodetector. Owing to the graphene electrode, the heterostructure devices build a strong electronic field at the surface of the InSe/WSe2 vdWs heterostructure. As a result, the device shows excellent optoelectronic characteristics such as broad band photoresponse ranging from 532 nm (visible) to 1100 nm (near infrared) including a high responsivity of 829.7 AW−1, a detectivity of 2.81×1014 Jones and a rapid photoresponse of 10 µs. Significantly, as presented photodetector device is applied in an imaging system, showcasing its capability for high-contrast photodetection. These findings highlight that the potential of graphene electrode integration in 2D vdWs heterostructure provides an effective roadmap for developing the advancing next generation of optoelectronic devices.

High-performance broadband photodetector with imaging application based on tantalum nickel selenium at room temperature

High-performance broadband photodetector with imaging application based on tantalum nickel selenium at room temperature

Staggered band alignment of n-Er2O3/p-Si heterostructure for the fabrication of a high-performance broadband photodetector

The low responsivity of conventional Silicon photodiodes in ultraviolet and near-infrared regimes restricts their utility as broadband photodetectors (BBPDs). Despite ongoing investigations into various p-n heterostructures for Silicon-based BBPDs, challenges such as high dark current (Idark), low collection efficiency, low detectivity, and compatibility issues with large-scale Silicon-based devices persist. In this context, we have fabricated relatively unexplored n-Er2O3/p-Si heterojunction-based BBPDs. Polycrystalline Er2O3 thin films (∼110 nm) were deposited on p-Si 〈100〉 substrates by radio frequency magnetron sputtering. Although this process induces a microstrain of approximately 0.022 and a dislocation density of about 0.00303/nm2, the presence of optically active defects is minimal, indicated by a low Urbach energy (∼0.35 eV). X-ray photoelectron spectroscopy (XPS) analysis confirms staggered band alignment at the heterointerface, facilitating efficient charge carrier separation and transport. Consequently, the In/p-Si/n-Er2O3/In device demonstrated significant BBPD properties– low Idark ∼0.15 μA (at +5 V), photo-to-dark current ratio (PDCR) ∼6.5 (at +5 V, 700 nm) with a maximum photoresponsivity ∼22.3 A W−1, and impressive detectivity (∼1013 Jones) even in UV-C region where traditional silicon-based photodetectors respond feebly. The device also demonstrates transient photo-response across an ultrawide spectrum (254 nm–1200 nm) with a fast rise time/fall time ∼79 ms/∼86 ms (at −5 V for 600 nm illumination). This work establishes a straightforward and reliable method for proper material engineering, surface texturing, staggered heterojunction formation, and high-performance BBPD fabrication with prominent broad-spectrum responsivity, sizeable detectivity, and fast response. The integration of these BBPDs with Silicon opens possibilities for their use in electronic devices containing optical switches for communications and broadband image sensors, enhancing their utility in various applications.

Strong Covalent Coupling in Vertically Layered SnSe2/PTAA Heterojunctions Enabled High Performance Inorganic-Organic Hybrid Photodetectors.

Controllable large-scale integration of two-dimensional (2D) materials with organic semiconductors and the realization of strong coupling between them still remain challenging. Herein, we demonstrate a wafer-scale, vertically layered SnSe2/PTAA heterojunction array with high light-trapping ability via a low-temperature molecular beam epitaxy method and a facile spin-coating process. Conductive probe atomic force microscopy (CP-AFM) measurements reveal strong rectification and photoresponse behavior in the individual SnSe2 nanosheet/PTAA heterojunction. Theoretical analysis demonstrates that vertically layered SnSe2/PTAA heterojunctions exhibit stronger C-Se covalent coupling than that of the conventional tiled type, which could facilitate more efficient charge transfer. Benefiting from these advantages, the SnSe2/PTAA heterojunction photodetectors with an optimized PTAA concentration show high performance, including a responsivity of 41.02 A/W, an external quantum efficiency of 1.31 × 104%, and high uniformity. The proposed approach for constructing large-scale 2D inorganic-organic heterostructures represents an effective route to fabricate high-performance broadband photodetectors for integrated optoelectronic systems.

Uncooled Broadband Photodetection via Light Trapping in Conformal PtTe2-Silicon Nanopillar Heterostructures.

Dirac semimetals have demonstrated significant attraction in the field of optoelectronics due to their unique bandgap structure and high carrier mobility. Combining them with classical semiconductor materials to form heterojunctions enables broadband optoelectronic conversion at room temperature. However, the low light absorption of layered Dirac semimetals substantially limits the device's responsivity in the infrared band. Herein, a three-dimensional (3D) heterostructure, composed of silicon nanopillars (SiNPs) and a conformal PtTe2 film, is proposed and demonstrated to enhance the photoresponsivity for uncooled broadband detection. The light trapping effect in the 3D heterostructure efficiently promotes the interaction between light and PtTe2, while also enhancing the light absorption efficiency of silicon, which enables the enhancement of the device responsivity across a broadband spectrum. Experimentally, the PtTe2-SiNPs heterojunction device demonstrates excellent photoelectric conversion behavior across the visible, near-infrared, and long-wave infrared (LWIR) bands, with its responsivity demonstrating an order-of-magnitude improvement compared to the counterparts with planar silicon heterojunctions. Under 11 μm laser irradiation, the noise equivalent power (NEP) can reach 1.76 nW·Hz-1/2 (@1 kHz). These findings offer a strategic approach to the design and fabrication of high-performance broadband photodetectors based on Dirac semimetals.

Environmental-Friendly Ag2S QD-Multilayer MoSe2 van Der Waals Heterostructure for High-Performance Broadband Photodetection.

Broadband photodetectors have drawn intensive attention owing to their wide application prospects in optical communication, imaging, astronomy, and so on. Two-dimensional transition-metal dichalcogenides (TMDs) are considered as highly potential candidates for photodetection applications, benefiting from their excellent photoelectric properties. However, most of the photodetectors based on TMDs suffer from low performance in the near-infrared (NIR) region due to the weak optical absorption efficiency near their absorption band edge, which severely constrains their usage for broadband optoelectronics. Here, by taking advantage of the high absorption coefficient and environment-friendly property of Ag2S quantum dots (QDs), the hybrid of multilayer MoSe2/Ag2S QDs is demonstrated with a high-performance broadband photodetection capability (532-1270 nm). The favorable energy band alignment of MoSe2/Ag2S QDs facilitates effective separation and collection of photogenerated carriers, and the heterostructure device exhibits significant enhancement of performance compared to the bare MoSe2 device. High responsivity, detectivity, and external quantum efficiency of 25.5 A/W, 1.45 × 1011 Jones, and 1070% are obtained at a low working voltage of 1 V under 980 nm illumination. The responsivity of the device can reach up to 1.2 A/W at 1270 nm wavelength, which is competitive to the commercial NIR photodetectors. Meanwhile, broadband imaging capability is demonstrated. Our work may open up a facile and eco-friendly approach to construct high-performance broadband photodetectors for next-generation compact optoelectronic applications.

Self-Powered Broadband Photodetector Based on NiO/Si Heterojunction Incorporating Graphene Transparent Conducting Layer.

In this study, a self-powered broadband photodetector based on graphene/NiO/n-Si was fabricated by the direct spin-coating of nanostructured NiO on the Si substrate. The current-voltage measurement of the NiO/Si heterostructure exhibited rectifying characteristics with enhanced photocurrent under light illumination. Photodetection capability was measured in the range from 300 nm to 800 nm, and a higher photoresponse in the UV region was observed due to the wide bandgap of NiO. The presence of a top graphene transparent conducting electrode further enhanced the responsivity in the whole measured wavelength region from 350 to 800 nm. The photoresponse of the NiO/Si detector at 350 nm was found to increase from 0.0187 to 0.163 A/W at -1 V with the insertion of the graphene top layer. A high photo-to-dark current ratio (≃104) at the zero bias indicates that the device has advantageous application in energy-efficient high-performance broadband photodetectors.

Self-Assembled BiGaSeAs Composite Superlattice-Structured Nanowire for Broad-Band Photodetection.

Photodetectors with a broad-band response range are widely used in many fields and are regarded as pivotal components of the modern miniaturized electronics industry. However, commercial broad-band photodetectors composed of traditional bulk semiconductor materials are still limited by complex preparation techniques, high costs, and a lack of mechanical strength and flexibility, which are difficult to satisfy the increasing demand for flexible and wearable optoelectronics. Therefore, researchers have been devoted to finding new strategies to obtain flexible, stable, and high-performance broad-band photodetectors. In this work, a novel self-assembled BiGaSeAs composite superlattice-structured nanowire was developed with a simple chemical vapor deposition method for easy fabrication. After the device assembling, the photodetector showed outstanding performance in terms of obvious Ion/Ioff (13.9), broad-band photoresponse (365-940 nm), excellent responsivity (1007.67 A/W), high detectivity (9.38 × 109 Jones), and rapid response (21 and 23 ms). The formation of microheterojunctions among various materials inside the nanowires also contributed to their extended broad-spectrum response and outstanding detection ability. These results indicate that the BiGaSeAs nanowires have potential applications in the field of flexible and wearable electronics.

High-performance broadband photodetector based on PtSe2/MoS2 heterojunction from visible to near-infrared region

High-performance broadband photodetector based on PtSe2/MoS2 heterojunction from visible to near-infrared region

Fabrication of Sb2Se3-based high-performance self-powered Visible-NIR broadband photodetector

Fabrication of Sb2Se3-based high-performance self-powered Visible-NIR broadband photodetector

A high-performance self-powered broadband photodetector based on vertical MAPbBr3/ZnO heterojunction

A high-performance self-powered broadband photodetector based on vertical MAPbBr3/ZnO heterojunction

Sm, Pt asymmetric n- and p-type contacts in WSe2 phototransistor for high-performance broadband photodetection

The development of high-performance broadband photodetectors working at room temperature is still attractive. The Schottky barrier phototransistor based on asymmetric junction seems to be endowed with such potential—as photodetectors with low device power consumption and high photoresponse; however, it is rarely studied. Herein, a Sm–WSe2–Pt phototransistor with asymmetric metal contacts is constructed, and it is systematically investigated for their electronic and photoelectronic tunability via gate voltage, wavelength, and illumination power density. It was found that the tunable photogating process dominates the photoresponse mechanism, which allows for an excellent broadband photodetection from 300 to 1000 nm wavelength. In addition, the responsivity (R) and specific detectivity (D*) at 450 nm can reach 1723 A/W and 2.3 × 1013 Jones, respectively, while that of infrared illumination of 900 nm can reach 4.7 A/W and 3.1 × 1010 Jones, respectively. In addition, the device exhibits obvious photoresponse at zero bias, the R and D* can reach up to 27 mA/W and 8.5 × 1010 Jones, which realizes self-driven photodetection. This work provides an optimal option for realizing high-integrated, high-performance, low-power-consuming, and room-temperature-working broadband photodetectors.

Carrier-recirculating broadband photodetector with high gain based on van der Waals In2Se3/MoS2 heterostructure

Two-dimensional (2D) materials present enormous potential in photoelectric detection, medical imaging, and neuromorphic vision applications due to their superior electronic and optoelectronic properties. Nevertheless, the photoelectric performance is restricted by the short lifetime of photogenerated carriers and weak optical absorption attributed to the atomic-scale thickness. This work demonstrates a novel high-gain photodetector based on van der Waals β-In2Se3/MoS2 heterostructure induced by carrier recirculation. In this structure, the photoexcited holes are trapped in the charge traps of MoS2 driven by the built-in electric field, which suppresses the recombination of photogenerated carriers, thus the electrons are repeatedly recycled across the In2Se3 channel after the generation of electron-hole pairs, achieving the high optical gain of 2.95 × 103. The responsivity, external quantum efficiency and specific detectivity of In2Se3/MoS2 photodetector can reach 616.77 A/W, 125900 %, and 1.03 × 1012 Jones at 638 nm, respectively, which are significantly higher than those of individual In2Se3 and MoS2 photodetector. More significantly, due to the enhanced optical absorption and interlayer transition, the photoresponse spectrum of In2Se3/MoS2 heterojunction is further extended to 1310 nm, which can be applied to broadband photodetection. Therefore, the In2Se3/MoS2 vdWs heterojunction photodetector provides a feasible approach to fabricate high-performance broadband photodetectors.

High performance broadband photodetector in two-dimensional metal dichalcogenides mediated by topologically protected surface state

Carrier scattering in photodetectors employing 2D dichalcogenide as an absorber impedes carrier transport. As scattering at the interface between the semiconductor and the electrode restricts carrier transport, it is essential to develop alternative electrode materials to achieve high photoresponsivity. A carrier can effectively move through a topologically protected Dirac surface state without scattering: i.e., alternatives such as topological insulators (TI) containing the surface state can effectively reduce scattering at the interface between the semiconductor and the electrode. In this stucy, TI Bi2Se3 with a well-ordered interfacial structure was used as a carrier transport layer (CTL) to effectively employ the topological surface state (TSS) for improving WSe2 photoresponsivity. At 520 nm, the Bi2Se3 TI-CTL photodetector has a photoresponsivity of up to 11.47 AW−1, 100 times higher than the photodevice using only Au electrodes. The photoresponsivity and time-resolved photoluminescence as a function of thickness indicate that TSS contributes to improved carrier separation with high carrier transfer efficiency, thereby affecting photocurrent generation. The fast carrier transfer through TSS helps efficiently separate electron-hole pairs and suppress recombination at the interface, generating ultra-fast and high-efficiency photocurrents in the broadband region (450–1550 nm). Therefore, TSS based on carrier dynamics can lead to further applications of next-generation optoelectronic devices.

High-performance broadband photodetectors based on sputtered NiOx/n-Si heterojunction diodes

High-performance broadband photodetectors based on NiOx/n-Si heterojunction were fabricated by radio frequency (rf) sputtering of NiO target at room temperature using 40, 60 and 80 W of power. The open circuit voltage is almost independent of the rf power with value of ∼0.33 V under illumination with red light with optical power of 3.71 mW/cm2, while the short circuit current depends on the sputtering power and has the highest value of 1.3 × 10−7 A (J = 1.45 × 10−3A/cm2) for diodes fabricated at 60 W. The responsivity (R) and specific detectivity in self-powered mode (Vb = 0 V) are higher for the 60 W photodiodes. The R values are 0.39, 0.61, 0.67 and 0.95 A/W under illumination with red, green, blue and UV lights with optical powers of 3.71, 1.03, 1.31 and 0.335 mW/cm2. The On/Off ratio of these diodes at Vb = 0 V is 1.5 × 104, 6.7 × 103, 9.4 × 103, 9.4 × 103 for illumination with the four lights. Capacitance-Voltage measurements indicate high quality of the NiOx/Si interface with low interface defect density and low density of bulk traps in NiOx for diodes obtained at the three powers. The responsivity of the heterojunction diodes obtained at 60 W at Vb = 0 V is among the highest reported in the literature for photodiodes based on NiOx. The quality of the rf sputtered NiOx layers and the low deposition temperature make them attractive for application in flexible optoelectronic devices.

Self-powered, thermally stable Sb2Se3-based high-performance broadband photodetector

High-performance broadband photodetectors are widely studied due to their unique significance in military and industrial applications. Vander Waals materials-based detector that simultaneously achieves a fast and high response are prerequisites for expanding the current capabilities of the optoelectronic device. Yet the thermal stability of the Vander Waals materials-based broadband (450 nm to 1250 nm) device is rarely addressed. Here, an antimony selenide (Sb2Se3) based photodetector is reported, which reveals high photo-responsivity and detectivity up to 924 mAW−1 (346 mAW−1) and 2.7 × 1010 Jones (1.0 × 1010 Jones) for the illumination wavelength 1064 nm (532 nm) under photovoltaic mode. Moreover, under 0 V-applied bias condition, the developed detector thermal stability was tested, and up to 100 °C devices disclosed a stable behavior. Further, the fabricated Sb2Se3-based broadband device was also tested under photoconductive mode. The photodetector demonstrates high responsivities of 1.5 × 104 mAW−1 (1.3 × 104 mAW−1) and 4.1 × 104 mAW−1 (3.8 × 104 mAW−1) for the illumination wavelength 532 nm and 1064 nm, respectively at room temperature (100 °C) under 0.5 V applied bias condition and 1 µW optical power. The design device can offer ideas for constructing high thermal stability and encouraging such materials in broadband photodetector applications. The state-of-the-art Sb2Se3-based detector can facilitate the translation of solution-processed optoelectronic applications from the laboratory to the marketplace.