Hybrid Photodetector Research Articles

Direct Photo‐Crosslinking Patterning for High‐Performance 0D–2D Hybrid Photodetectors

AbstractHigh‐performance 0D–2D hybrid photodetectors integrated with a crosslinker for direct pattering of quantum dots on the large‐scale synthesized MoS2 layer are reported. In the patterned hybrid structure, QD layers are patterned with a resolution of up to 2 µm, ensuring high precision. Enhanced charge transfer from QDs to 2D materials is confirmed using PL quenching, TR‐PL, and UPS analysis. As a result, the QD/2D hybrid photodetectors with crosslinker‐assisted direct patterning demonstrated a remarkable photoresponsivity of ≈105 A W−1 and a specific detectivity of over 1011 Jones, attributed to the difference in built‐in potential. The crosslinker patterning of QDs opens up potential applications for the photodetectors in highly integrated image sensors and can be further extended to high‐resolution display industries, eliminating unnecessary fabrication processes.

Air-stable and UV-NIR broadband photodetectors utilizing graphene and core/shell quantum dots hybrid heterostructure

Photodetectors based on PbSe quantum dots (QDs) are commonly used for light detection in the near-infrared (NIR) region. Nevertheless, the performance of photodetectors based on PbSe QDs is constrained by ineffective carrier transfer and poor photo and thermal stabilities. Herein, a promising strategy that harnesses PbSe/PbS core/shell QDs structures is developed and demonstrated to enhance the long-term stability of photodetectors, further combining with graphene to form hybrid heterojunctions that effectively promote carrier transfer. As a result, the devices exhibit a broad photoresponse to the incident light at range of 365–1250 nm, and also possess a high photosensitivity of 1.5 × 104 A/W and a high detectivity of 4.0 × 1013 Jones. Moreover, the lifetime of graphene-PbSe/PbS core/shell QDs hybrid photodetector was 9 times greater than that of uncoated QDs devices. The enormous boost might be attributed to the passivation and protection provided by the core–shell structure, and graphene’s efficient extraction of charge carriers.

Mixed-Dimensional Heterostructure Photodetector Based on Bi2O2Se Nanosheets and PbS Quantum Dots

Due to their exceptional electronic and optical properties, two-dimensional materials have emerged as one of the most promising candidates for future optoelectronic detection. However, optoelectronic detectors based on two-dimensional transition metal materials still face challenges due to factors such as limited absorption coefficients and carrier recombination. In this study, we combine two-dimensional Bi2O2Se with PbS quantum dots to prepare a hybrid heterojunction, effectively broadening the detection range and significantly enhancing the photoresponse rate. The hybrid photodetector exhibited a remarkable photoresponsivity of 14.89 A/W at 450 nm and demonstrated broadband detection capabilities from visible (405 nm) to near-infrared (1350 nm) light illumination. Moreover, the hybrid device showed reduced photocurrent response and recovery times, highlighting its improved performance over bare Bi2O2Se photodetectors. This work underscores the potential of hybrid heterojunctions for enhancing optoelectronic detection capabilities, paving the way for advanced applications in various fields.

A parylene/graphene UV photodetector with ultrahigh responsivity and long term stability

Long term stability, high responsivity, and fast response speed are essential for the commercialization of graphene photodetectors (GPDs). In this work, a parylene/graphene UV photodetector with long term stability, ultrahigh responsivity and fast response speed, is demonstrated. Parylene as a stable physical and chemical insulating layer reduces the environmental sensitivity of graphene, and enhances the performances of GPDs. In addition, utilizing bilayer electrodes reduces the buckling and damage of graphene after transferring. The parylene/graphene UV photodetector exhibits an ultrahigh responsivity of 5.82 × 105 AW−1 under 325 nm light irradiation at 1 V bias. Additionally, it shows a fast response speed with a rise time of 80 μs and a fall time of 17 μs, and a long term stability at 405 nm wavelength which is absent in the device without parylene. The parylene/graphene UV photodetector possesses superior performances. This paves the way for the commercial application of the high-performance graphene hybrid photodetectors, and provides a practical method for maintaining the long term stability of two dimensional (2D) materials.

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.

Highly Porous ZnO/CNT Hybrid Microclusters for Superior UV Photodetection.

The formation of nanoscale junctions among nanoparticles in self-assembled nanostructures is crucial for improving both interfacial conductivity and structural integrity. However, the inherent reliance on weak van der Waals forces to hold nanoparticles together poses challenges in developing commercially viable devices due to their inefficient carrier transport characteristics. This study presents the successful integration of carbon nanotubes (CNTs) into highly porous nanomicrocluster arrays of ZnO, resulting in the formation of cohesive and crack-free highly porous ZnO/CNT heterojunction films. This integration marks a significant improvement in UV photodetection performance, demonstrating a record-high photocurrent to dark current ratio of 3.3 × 106 and an exceptional responsivity of 18.5 A/W at a low bias of 0.5 V and under an ultra low light density of 25 μW/cm2. These findings underscore the efficacy of this high-performance structure as a versatile and scalable platform technology for the rapid, cost-effective fabrication of hybrid photodetectors in wearable and portable devices.

Mixed-Dimensional van der Waals Heterostructure (2D ReS2/0D MoS2 Quantum Dots)-Based Broad Spectral Range with Ultrahigh-Responsive Photodetector.

The remarkable properties of two-dimensional (2D) materials have led to significant advancements in photodetection and optoelectronics research. Currently, there are many successful methods that are employed to improve the responsivity of photodetectors, but the limited spectral range of the device remains a limitation. This work demonstrates the development of a mixed-dimensional (2D/0D) hybrid photodetector device fabricated using chemical vapor deposition (CVD)-grown monolayer ReS2 and solution-processed MoS2 quantum dots (QDs). The mixed dimensionality of 2D (ReS2) and zero-dimensional (0D) MoS2 QDs assist in improving the spectral range of the device [ultraviolet (360 nm) to near-infrared (780 nm)]. Further, due to the work function difference between ReS2 and MoS2 QDs, the built-in electric field across the mixed-dimensional interface promotes effective charge separation and migration, resulting in improved responsivities of the device. The calculated responsivities of the fabricated photodetector are 5.4 × 102, 3.3 × 102, and 2.6 × 102 A/W when subjected to visible, UV, and NIR light illumination, which is remarkable when compared to the existing reports on broadband photodetection. The mixed-dimensionality heterostructure coupled with contact engineering paves the way for highly responsive broadband photodetectors for potential applications in security, healthcare, etc.

Simulation of electron transport in a catoptric photomultiplier tube concept for large rectangular scintillator crystals

Spectroscopic scintillation detector form factors have been guided primarily by the design of commercially available photonic sensors. These devices, such as photomultiplier tubes, silicon photomultipliers, and hybrid photodetectors have underperformed in one or more areas such as size, power consumption, and resolution. A novel photomultiplier tube having a 50.8×152.4 mm2 rectangular window, utilizing a reflection-mode photocathode, and a low-gain, miniaturized dynode set is considered here to improve photosensor packaging while enabling high-efficiency, low-resolution scintillation spectroscopy with large, planar scintillators. Using a phenomenological multiphysics simulation process informed by empirical data, photoelectron collection efficiency, single-photoelectron response, electron transit time, and transit time spread have been modeled over a range of operating potentials. At 750 V between the photocathode and anode, 72.5% of photoelectrons are collected at the first dynode, and the average gain is estimated to be 805. The most probable transit time is 14.9 ns, with a transit time spread of 2.7 ns full-width at half-maximum.

Two-Step Ligand-Exchange-Assisted Charge Transfer in Graphene/PbS Quantum Dots Hybrid Near-Infrared Photodetector

Two-Step Ligand-Exchange-Assisted Charge Transfer in Graphene/PbS Quantum Dots Hybrid Near-Infrared Photodetector

Surface plasmon resonance assisted donor–acceptor type covalent polymeric framework for hybrid photodetectors

In this paper, a surface plasmon resonance assisted hybrid photodetector (PD) made of a low bandgap covalent polymeric framework material is experimentally demonstrated. The PD demonstrated a broadband photodetection capability ranging between 350 and 1550 nm with subsecond transients. The fabricated hybrid PD offered a remarkable responsivity and external quantum efficiency of 42.87 A/W and 11 873% at 410 nm, respectively. The peak detectivity is recorded to be 7.43×1013 Jones at 400 nm. Up to 1550 nm, the hybrid PD offered a responsivity > 0.4 A/W, thereby showcasing its efficacy even for the near-infrared signals. The time-dependent photoresponse study estimated the rise time and fall time of the fabricated PD to be approximately 0.31 and 0.22 s, respectively.

P-type π-conjugated BTPDS-8 organic molecule for broadband hybrid photodetector with organic/inorganic heterostructure

A novel p-type π-conjugated organic small molecule 3,7-bis(4-([2,2′:6′,2''-terpyridin]−4′-yl)phenyl)− 5H-dibenzo[a,d][7]annulen-5-one (named as BTPDS-8) in which terpyridinyl units are linked to the dibenzosuberenone backbone by a phenyl bridge was successfully synthesized in four reaction steps. The synthesized organic material BTPDS-8 was fully characterized using 1H NMR, 13C NMR, IR, and HRMS spectroscopy techniques. Then, eleven BTPDS-8/Si heterojunctions were fabricated having non-linear current-voltage characteristics. Among these devices, the one with the highest rectification ratio (with 8.43 ×105) was analyzed in detail under UV and IR light as well as different intensities of visible light. Experimental results showed that the device has good photoresponse performance under any light source in addition to self-driven mode characteristics. It was observed that the saturation current and barrier height increased, and the ideality factor decreased, depending on the light intensity under visible light. Photocurrent, on/off ratio, responsivity, detectivity and NPDR were calculated from the optical measurements. The broad spectrum photoresponse of the BTPDS-8/Si heterojunction from UV to IR demonstrated that the device has the potential to be used as a broadband photodetector. The best performance was obtained under 850 nm IR light. The detectivity values under IR light were 1.22 × 1010 Jones and 7.53 × 109 Jones for V= 0.0 volts (self-driven mode) and V= −2.0 volts, respectively.

High-sensitivity hybrid MoSe2/AgInGaS quantum dot heterojunction photodetector.

Zero-dimensional (0D)-two-dimensional (2D) hybrid photodetectors have received widespread attention due to their outstanding photoelectric performances. However, these devices with high performances mainly employ quantum dots that contain toxic elements as sensitizing layers, which restricts their practical applications. In this work, we used eco-friendly AgInGaS quantum dots (AIGS-QDs) as a highly light-absorbing layer and molybdenum diselenide (MoSe2) as a charge transfer layer to construct a 0D-2D hybrid photodetector. Notably, we observed that MoSe2 strongly quenches the photoluminescence (PL) of AIGS-QDs and decreases the decay time of PL in the MoSe2/AIGS-QDs heterojunction. The MoSe2/AIGS-QDs hybrid photodetector demonstrates a responsivity of 14.3 A W-1 and a high detectivity of 6.4 × 1011 Jones. Moreover, the detectivity of the hybrid phototransistor is significantly enhanced by more than three times compared with that of the MoSe2 photodetector. Our work suggests that 0D-2D hybrid photodetectors with multiplex I-III-VI QDs provide promising potential for future high-sensitivity photodetectors.

MXene-antenna electrode with collective multipole resonances.

Two-dimensional transition metal carbides and nitrides (MXene-s) are the focus of extensive research due to their exceptional potential for practical applications. We study nanostructured MXene layers to design photodetector electrodes and increase their response through hot-electron generation. We demonstrate that the lattice arrangement plays a crucial role in exciting strong optical resonances in the nanostructured MXene, specifically Ti3C2Tx, despite its high loss and weak optical resonances in an isolated antenna. We use numerical simulations and analytical calculations with coupled dipole-quadrupole lattice sums for designing photodetector electrodes. We also provide proof-of-concept experimental demonstration of the enhanced resonances even for the case of lossy materials. We report on the excitation of strong lattice resonances of the MXene antenna array with enhanced absorption, resulting in a more efficient generation of hot electrons. Our findings reveal that a multi-period array of MXene antennas can improve narrowband and broadband photodetector functionality. We propose highly efficient absorbers based on MXene metasurfaces and transforming electrodes into hybrid photodetectors using MXene antennas to enhance their performance.

Highly efficient organic-graphene hybrid photodetectors via molecular peripheral editing.

Hybrid systems based on graphene and organic molecules are highly appealing for "correcting" the limited optoelectronic properties of 2D materials. However, an in-depth understanding of the correlation between the structure of the molecular sensitizer and the physical properties of the hybrid toward high-performance organic-graphene hybrid photodetectors remains elusive. Herein, an ad hoc molecular design via a peripheral editing approach on the organic molecules is employed to elucidate the structure-property relationship when interfaced with graphene forming hybrid systems. Efficient doping of graphene can be attained by physisorption of tetrathiafulvalene molecules exposing electron-donating peripheral groups, benefiting from a strong coupling yielding efficient charge transfer, ultimately leading to photodetectors with an ultra-high responsivity of 1.1 × 107 A W-1 and a specific detectivity of 6.5 × 1014 Jones, thereby outperforming state-of-the-art graphene-based photodetectors. These results offer valuable insights for future optimization of graphene-based photodetectors through molecular functionalization.

Fabrication of high-performance double-sided self-biased ZnO/P3HT based hybrid photodetector

Fabrication of high-performance double-sided self-biased ZnO/P3HT based hybrid photodetector

Silicon distyryl-BODIPY hybrid photodiode: moving a step ahead from organic interface layer to type II band alignment

Organic-inorganic heterojunctions are becoming an attractive topic of research for their applications in hybrid photodetectors, solar cells, resistive switching memory devices etc. The easy chemical synthesis and low-cost fabrication for organic thin films come with the benefit of high light absorptivity, high fluorescence quantum yield and band gap tunability along with high charge carrier lifetime that could be combined with the existing silicon-based technology. In this aspect, various organic dyes utilised as an interfacial layer with silicon Schottky junction are reported earlier. However, the photo responses are quite limited. Here, in this report, a Type II Silicon/Distyryl-BODIPY p-n junction has been proposed as an organic-inorganic hybrid photodetector which has not been explored extensively yet. The transformation from a mere organic interfacial layer to band aligned junction enhances the charge carrier separation providing higher photo-responsive behaviour. With the simple spin-coating technique, the Distyryl-BODIPY derivative with phenolic functionalities is coated to fabricate the p-n junction diode. To further improve the performance, pyramidal surface texturization on silicon is deployed using wet chemical etching that supplements the light absorption with internal reflections. Both the devices have been investigated for their photo-response characteristic where a high photo-responsivity of 4353 A W−1 is attained for the textured device as compared to 118 A W−1 for the planar silicon device at a − 3 V bias with an ultra-high specific detectivity of 1012 Jones and 1010 Jones respectively. The behaviours of interfacial states have been demonstrated using the capacitance (C), conductance (G) and series resistance (RS) vs voltage (V) curves at different frequencies. Further calculations of interfacial state density revealed the existence of 1000 times higher interfacial states in planar device leading to lower performance as compared to pyramidal device. The findings in this report suggest that dye-based organic-inorganic heterostructures find potential applications in photodetectors and other optoelectronic devices.

Mega broadband photoresponsivity in degradation-controlled super-halide PF6 substituted Perovskite@graphene hybrid photodetectors

We present, probably for the first time, the use of super-halide PF6 as a substitution for iodine in the bulk precursor phase of FAPbI3 for stable perovskite@graphene photodetectors. Our novel approach confers improved stability of perovskite, as demonstrated by synchrotron-based time-dependent nano-X-ray Fluorescence mapping of iodine. We observed a predominantly high α-phase (with weaker δ and PbI2 phases) in the superior 10 % PF6-substituted perovskite, as revealed by synchrotron-based GIWAXS. Our FAPbI3-x(PF6)x@graphene photodetectors exhibited exceptional performance under power-dependent broadband illumination. In contrast to pure FAPbI3@graphene devices (x = 0), which showed time-dependent bi-directional photoresponse indicative of degradation, our 10 % PF6-substituted perovskite@graphene devices (x = 0.1) displayed unprecedented, positive, and stable photoresponsivity (∼1.01 × 106 A W−1), along with a high detectivity (D*) of 5 × 1014 Jones. Our devices also demonstrated remarkable sensitivity to signals from domestic appliances, exhibiting response times ranging from 93 to 101 ms. We model the photodetection mechanism using experimental band structure measurements to explain our results. Our findings suggest that our FAPbI3-x(PF6)x@graphene photodetectors hold great promise for a range of applications in the fields of optoelectronics and sensing. In addition, our findings can contribute to the development of more stable and efficient perovskite solar cells, thereby advancing the solar cell research field.

Highly responsive self-driven broadband hybrid photodetector with high detectivity and on/off ratio based on Hibiscus sabdariffa

A Hibiscus sabdariffa (HBS)/n-Si hybrid photodetector was fabricated and it was observed that the device has a high rectification ratio of 10.2 × 104 in dark and superior photoresponse at different intensities of visible light in addition to UV and IR lights. The non-linear response to light intensity in visible light was attributed to phase change effects and the presence of traps, which are the result of the hibiscus sabdariffa’ response to light. The responsivity at 850 nm reaches 1.16 A W−1 (at V = −2.0 V) and a high specific detectivity of 2.0 × 1012 Jones (for self-driven mode) with an external quantum efficiency of 411% was obtained. In addition, in self-driven mode of UV and IR lights, the highest on/off ratio and NPDR values reached ∼105 and ∼109 W−1 levels, respectively. Moreover, HBS/n-Si hybrid broad-band photodetector showed long-term stability (40 days) without encapsulation both in the dark and under the light.

Deposition of Transparent Ag Nanowires‐Based Top Electrode for the Development of Double‐Side Green Light Hybrid Photodetector

Herein, various silver nanowires (AgNWs) deposition techniques, i.e., spin coating, Mayer rod coating, and spray coating are used to fabricate ZnO/P3HT‐based double‐side hybrid photodetectors and their photoresponse for 520 nm green light has been compared. The electrodes are coated over the polyethylene terephthalate sheet separately and laminated over the indium tin oxide (ITO)/ZnO/P3HT. Mayer rod‐coated electrodes are found to have a sheet resistance (Rsh) of 24 Ω Sq.−1 and a light transmission of 91%. Additionally, spin‐ and spray‐coated AgNW electrodes exhibit Rsh of 20 and 23 Ω Sq.−1, respectively, along with 80% and 85% transparencies. As the device consists of transparent electrodes on both sides, it can detect light from both the top and bottom sides. Mayer rod‐coated AgNW electrode‐based device has produced better photosensitivity of 1500 (for ITO side illumination) and 630 (for AgNWs side illumination) at λ = 525 nm. Further, the device has demonstrated the responsivity of 124 mAW−1 and specific detectivity of 3 × 1011 Jones.

Numerical evaluations of curcumin organic molecule and an experimental study on hybrid photodetector performance in visible and UV regions

In this work, we demonstrate efficient self-powered visible and UV photodetectors with hybrid organic-inorganic materials based on organic curcumin pigment (CU), having C21H20O6 as a molecular formula, and inorganic silicon semiconductor in CU/n-Si architecture. The optical absorption spectrum of the CU film is investigated by UV–Visible absorption features with a broad emission band. The self-powered behavior of the CU/n-Si photodetector has been attributed to the built-in electric field formed between the CU and n-Si heterojunction interface. The optical performance of the hybrid photodetector, both under different light intensities of visible light and under 365 and 395 nm UV light, is investigated in detail by current-voltage measurements. CU/n-Si heterojunction photodetector exhibits excellent UV detecting capability and good photoresponsivity. The photo-response of the CU/n-Si device is slightly higher under 395 nm UV light than 365 nm one. The R and D* values obtained at 395 nm are 13.19 AW-1(at −2 V) and 1.22 × 1011 Jones (zero bias), respectively. Furthermore, under 365 and 395 nm light, the ON/OFF values are obtained as about 105. According to the simulated result, the curcumin molecule has great physical properties such as antibacterial activity and nonlinear optical response which makes it a potential candidate for biomedical and optoelectronic applications.