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Bandgap engineering in CuO nanostructures: Dual-band, broadband, and UV-C photodetectors
摘要： In this work, the bandgap of CuO (p-type semiconductor) has been engineered from an indirect bandgap of (cid:2)1 eV to a direct bandgap of 4 eV just by tuning the nanostructure morphology and midgap defect states. The absorption in near-infrared (NIR) and visible regions is ordinarily suppressed by controlling the growth parameters. Considering the increasing scope and demand of varying spectral range (UV-C to NIR) photodetectors, the systematic variation of the available density of states (DOS) at a particular energy level in CuO nanostructures has been utilized to fabricate dual-band (250 nm and 900 nm), broadband (250 nm–900 nm), and UV-C (250 nm) photodetectors. The sensitivity and detectivity of the photodetector for broadband detectors were (cid:2)103 and 2.24 (cid:3) 1011 Jones for the wavelengths of 900 nm and 122 and 2.74 (cid:3) 1010 Jones for 250 nm wavelength light, respectively. The UV-C detector showed a sensitivity of 1.8 and a detectivity of 4 (cid:3) 109 Jones for 250 nm wavelength light. A plausible mechanism for the photoconduction has been proposed for explaining the device operation and the effect of variation in available DOS. The obtained photodetectors are the potential candidates for future optoelectronic applications.
关键词： Broadband photodetectors,Bandgap engineering,CuO nanostructures,Dual-band photodetectors,UV-C photodetectors
更新于2025-09-23 15:21:01
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Surface Engineered Hybrid Corea??Shell Sia??Nanowires for Efficient and Stable Broadband Photodetectors
摘要： Silicon nanostructures have gained intensive interest to develop broadband photodetectors at a large-scale due to their excellent electronic properties. Herein, Si-nanowires (SiNWs) decorated with reduced graphene oxide:carbon quantum dots (rGO:CQDs) nanocomposite (NC), as core–shell heterojunction building blocks for broadband (ultraviolet (UV)–near infrared (NIR)) photodetectors (PDs), are demonstrated. The SiNWs and CQDs are synthesized by wet-chemical etching and facile pyrolysis methods, respectively. Photogenerated carriers are transported through rGO because of its high electron mobility and favorable band alignment with CQDs and Si. Further, to minimize the recombination of photogenerated carriers, and enhance the response in the visible region, plasmon-enhanced AuCQDs are incorporated in the shell matrix. The optimized heterostructure (rGO:AuCQDs/undoped CQDs/SiNWs) is sensitive to a broad wavelength range covering the UV to NIR (360 to 940 nm) region, manifests the excellent responsivity of 16 A W?1 at 360 nm, detectivity (D*) of 2.2 × 1013 Jones, and noise equivalent power as low as 2.8 fW Hz?1/2. The optimized PDs heterostructure demonstrates excellent air-stability after 8 days of illumination without any encapsulation or protective coating. The proposed simple, cost-effective, and Si-process-line compatible fabrication of Si-based PD device structure imposes a great promise for highly efficient and stable advanced futuristic optoelectronic devices.
关键词： core–shell heterostructure,detectivity,responsivity,broadband photodetectors,reduced graphene oxide,carbon quantum dots,Si nanowires
更新于2025-09-23 15:21:01
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Solutiona??Processed, Selfa??Powered Broadband CH <sub/>3</sub> NH <sub/>3</sub> PbI <sub/>3</sub> Photodetectors Driven by Asymmetric Electrodes
摘要： In general, the fabrication of high-performance, self-powered broadband photodetectors based on traditional semiconducting thin films is tedious and costly. Here, in this paper a high-performance, solution-processed, and self-powered CH3NH3PbI3 (MAPbI3) nanocrystal based photodetector ITO/MAPbI3/Ag is presented, and it shows broadband photoresponse from the visible to the near-infrared wavelength region. The pronounced enhanced performance of the photodetector is due to taking the advantage of the built-in electric field induced by the work function difference of two electrodes. The optimized photodetector shows a responsivity of 4.9 and 1.42 A W?1 with a specific detectivity of 7.6 × 1013 and 1.77 × 1013 Jones under 19 μW cm?2 white light illumination and 26 μW cm?2 808 nm illumination at zero bias, respectively. Therefore, such a concept of simple device geometry and feasible technique will open up a new and promising avenue for the fabrication of self-powered photodetectors and the development of imaging devices.
关键词： ligand-assisted reprecipitation (LARP),CH3NH3PbI3 nanocrystals,broadband photodetectors,photocurrent imaging
更新于2025-09-23 15:21:01
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Solutiona??Processed Flexible Broadband Photodetectors with Solutiona??Processed Transparent Polymeric Electrode
摘要： Room-temperature solution-processed flexible photodetectors with spectral response from 300 to 2600 nm are reported. Solution-processed polymeric thin film with transparency ranging from 300 to 7000 nm and superior electrical conductivity as the transparent electrode is reported. Solution-processed flexible broadband photodetectors with a 'vertical' device structure incorporating a perovskite/PbSe quantum dot bilayer thin film based on the above solution-processed transparent polymeric electrode are demonstrated. The utilization of perovskite/PbSe quantum dot bilayer thin film as the photoactive layer extends spectral response to infrared region and boosts photocurrent densities in both visible and infrared regions through the trap-assisted photomultiplication effect. Operated at room temperature and under an external bias of -1 V, the solution-processed flexible photodetectors exhibit over 230 mA W-1 responsivity, over 1011 cm Hz1/2/W photodetectivity from 300 to 2600 nm and ≈70 dB linear dynamic ranges. It is also found that the solution-processed flexible broadband photodetectors exhibit fast response time and excellent flexibility. All these results demonstrate that this work develop a facile approach to realize room-temperature operated ultrasensitive solution-processed flexible broadband photodetectors with 'vertical' device structure through solution-processed transparent polymeric electrode.
关键词： perovskite photodetectors,broadband photodetectors,PbSe quantum dots,flexible electronics
更新于2025-09-23 15:19:57
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Enhanced Performances of p-Si/n-ZnO Self-powered Photodetector by Interface State Modification and Pyro-phototronic Effect
摘要： ZnO based self-powered photodetector (PD) has great application potential in distributing sensor networks and internet of things. However, a large number of surface or interface states within ZnO limit its performance improvement. Here, the surface and interface states of ZnO is greatly eliminated by ultraviolet irradiation as an interfacial modification engineering. Reduction of interface states reduces ohmic resistance, also enhances the tuning role of pyro-phototronic effect. And the transient response currents of the self-powered PD are thus significantly improved with a maximal enhancement factor of more than 5900% for the 325-785 nm broadband stimulating beams. The corresponding response time is decreased to few milliseconds or sub-milliseconds. The results indicate that surface-state reduction of ZnO can effectively enhance the modifying role of pyro-phototronic effect and greatly improve the response performances of the self-powered broadband PDs with great application demands in Internet of things, broad spectral detecting and imaging, and smart optoelectronic devices.
关键词： Self-powered,ultraviolet irradiation,interface states,pyro-phototronic effect,broadband photodetectors
更新于2025-09-23 15:19:57
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Interlayer Transition in a vdW Heterostructure toward Ultrahigh Detectivity Shortwave Infrared Photodetectors
摘要： Van der Waals (vdW) heterostructures of 2D atomically thin layered materials (2DLMs) provide a unique platform for constructing optoelectronic devices by staking 2D atomic sheets with unprecedented functionality and performance. A particular advantage of these vdW heterostructures is the energy band engineering of 2DLMs to achieve interlayer excitons through type-II band alignment, enabling spectral range exceeding the cutoff wavelengths of the individual atomic sheets in the 2DLM. Herein, the high performance of GaTe/InSe vdW heterostructures device is reported. Unexpectedly, this GaTe/InSe vdWs p–n junction exhibits extraordinary detectivity in a new shortwave infrared (SWIR) spectrum, which is forbidden by the respective bandgap limits for the constituent GaTe (bandgap of ≈1.70 eV in both the bulk and monolayer) and InSe (bandgap of ≈1.20–1.80 eV depending on thickness reduction from bulk to monolayer). Specifically, the uncooled SWIR detectivity is up to ≈1014 Jones at 1064 nm and ≈1012 Jones at 1550 nm, respectively. This result indicates that the 2DLM vdW heterostructures with type-II band alignment produce an interlayer exciton transition, and this advantage can offer a viable strategy for devising high-performance optoelectronics in SWIR or even longer wavelengths beyond the individual limitations of the bandgaps and heteroepitaxy of the constituent atomic layers.
关键词： interlayer transitions,2D materials,vdW heterostructures,broadband photodetectors,shortwave infrared
更新于2025-09-19 17:13:59
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Broadband polymer photodetectors with a good trade-off between broad response and high detectivity by using combined electron-deficient moieties
摘要： High-performance broadband photodetectors based on low-bandgap conjugated polymers are scarce due to a trade-off between the photoresponse range and device performance. In this work, the polymers with structural features responsible for both broad response and high detectivity are realized by using the combined electron deficient moieties at the molecular level. Based on the electron-deficient diketopyrrolopyrrole (DPP) and benzothiadiazole (BT), the combined units of DPP-DPP and DPP-BT-DPP are deemed more electron deficient and were successfully incorporated into the corresponding polymers. The arrangement of electron deficient moieties in the polymer mainchain were found to be able to greatly affect the absorption profile, energy level, molecular stacking, and blend film morphology. Consequently, the photodetector based on the polymer with DPP-BT-DPP acceptor exhibited the D* value of over 1012 Jones in the spectral region of 320–930 nm under -0.1 V bias.
关键词： low-bandgap conjugated polymers,electron deficient moieties,high detectivity,DPP,broadband photodetectors,BT
更新于2025-09-16 10:30:52
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All-solution-processed UV-IR broadband trilayer photodetectors with CsPbBr3 colloidal nanocrystals as carriers-extracting layer
摘要： Colloidal quantum dots (CQDs) are very promising nanomaterials for optoelectronics due to their tunable bandgap and quantum confinement effect. Especially, all-inorganic CsPbX3 (X=Br, Cl and I) perovskite nanocrystals (NCs) have attracted enormous interests owing to their promising and exciting applications in photovoltaic devices. In this paper, all-solution-processed broadband photodetectors ITO/ZnO/CsPbBr3/PbS/Au with high-performance were presented. The role of CsPbBr3 QDs layer as the carriers-extracting layer in the trilayer devices was discussed. As compared with bilayer device ITO/ZnO/PbS/Au, both the dark currents and photocurrents under illumination from UV-IR broadband trilayer photodetector ITO/ZnO(80nm)/PbS(150nm)/CsPbBr3(50nm)/Au are enhanced, but the trilayer photodetector ITO/ZnO(80nm)/CsPbBr3(50nm)/PbS(150nm)/Au showed a maximum specific detectivity (D*) of 1.73×1012 Jones with a responsivity (R) of 5.31 A/W under 6.8 mW/cm2 405 nm illumination. However, another trilayer photodetector ITO/ZnO(80nm)/PbS(150nm)/CsPbBr3(50nm)/Au showed a maximum D* of 8.3×1012 Jones with a R of 35 A/W under 1.6 mW/cm2 980 nm illumination. Further, the underlying mechanism for the enhanced performance of trilayer photodetectors was discussed. Thus, this strategy of all-solution-processed heterojunction configuration paves a facile way for broadband photodetectors with high-performance.
关键词： broadband photodetectors,all-solution-processed heterojunction,Colloidal quantum dots (CQDs),CsPbBr3 perovskite nanocrystals,carrier-extraction layer
更新于2025-09-12 10:27:22
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High responsivity and fast UV-Vis-SWIR photodetector based on Cd3As2/MoS2 heterojunction
摘要： High responsivity, fast response time, ultra-wide detection spectrum are pursuing goals for state-of-art photodetectors. Cd3As2, as a three-dimensional (3D) Dirac semimetal, has zero-bandgap, high light absorption rate in broad spectral region, and higher mobility than graphene at room temperature. However, photoconductive detectors based Cd3As2 suffer low quantum efficiency due to the absence of high built-in field. Here, Cd3As2 nanoplate/multilayer MoS2 heterojunction photodetector was fabricated and achieved a quite high responsivity of 2.7×103 A/W at room temperature. The photodetector exhibits a short response time of in broad spectra region from ultraviolet (365 nm) to short-wavelength-infrared (1550 nm) and reached 65 μs at 650 nm. This work provides a great potential solution for high-performance photodetector and broadband imaging by combining 3D Dirac semi-metal materials with semiconductor materials.
关键词： 3D Dirac semimetals,broadband,photodetectors,responsivity,heterojunction
更新于2025-09-11 14:15:04