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Efficiency and spectral performance of narrowband organic and perovskite photodetectors: a cross-sectional review
摘要： The capability of detecting visible and near infrared light within a narrow wavelength range is in high demand for numerous emerging application areas, including wearable electronics, the Internet of Things, computer vision, artificial vision and biosensing. Organic and perovskite semiconductors possess a set of properties that make them particularly suitable for narrowband photodetection. This has led to rising interest in their use towards such functionality, and has driven remarkable progress in recent years. Through a comparative analysis across an extensive body of literature, this review provides an up-to-date assessment of this rapidly growing research area. The transversal approach adopted here focuses on the identification of: (a) the unifying aspects underlying organic and perovskite narrowband photodetection in the visible and in the near infrared range; and (b) the trends relevant to photoconversion efficiency and spectral width in relation to material, device and processing strategies. A cross-sectional view of organic and perovskite narrowband photodetection is thus delineated, giving fresh insight into the status and prospects of this research area.
关键词： narrowband organic photodetectors,narrowband perovskite photodetectors,NIR photodetectors,colour sensors,spectral selectivity
更新于2025-09-23 15:19:57
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Narrowbanda??Absorptiona??Type Organic Photodetectors for the Fara??Red Range Based on Fullerenea??Free Bulk Heterojunctions
摘要： Spectrally-selective photodetection via organic semiconductors manifesting narrowband absorption (NBA photodetection) is highly attractive for emerging applications that require ultrathin, lightweight, and low-cost solutions. While successful over mainstream color bands, NBA photodetectors have struggled so far to meet the functional and/or performance demands at longer wavelengths, importantly in the far-red (700–750 nm), a range relevant to diverse applications in analytical biology, medical diagnostics, remote sensing, etc. In consideration of the potential of a nonfullerene-acceptor route to address this challenge, the narrowband photodetection capabilities of SBDTIC, a recently-developed benzodithiophene-based acceptor with narrowband absorption in the far-red, are explored. Two bulk-heterojunction NBA configurations are considered, in which SBDTIC is combined with a donor either absorbing also in the far-red, or transparent through the visible. It is found that the latter configuration provides superior narrowband functionality, with peak detectivity of 1.42 × 1013 Jones and spectral width of 141 nm—the highest detectivity to date for NBA far-red-selective photodetectors, and the smallest spectral width of all solution-processed implementations. In self-powered operation, such photodetectors additionally present a quasilinear response over a photocurrent range of least four orders of magnitude, and respond in the microsecond range, further evidencing the suitability of this approach to address the wealth of target applications.
关键词： far-red,nonfullerene acceptors,narrowband-absorption photodetectors,organic photodetectors,narrowband photodetectors
更新于2025-09-23 15:19:57
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Organic Photodetectors: Materials, Structures, and Challenges
摘要： Owing to the advantages of solution processing, light weight, low cost and mechanical flexibility, organic photodetectors (OPDs) have attracted great interests and become a new member in the photodetector family. Nowadays, OPDs have made considerable progress and can be compared with traditional photodetectors in some aspects. They present potential applications in portable and wearable devices. However, there are still some issues that need to be overcome and there is great room for new development. In this essay, the significant advances of OPDs are summarized and discussed, and the future for OPDs is prospected from the aspects of materials, structures and applications. We believe that this essay can inspire new ideas for developing innovative high-performance OPDs and exploring their practical applications.
关键词： materials,organic photodetectors,structures,applications
更新于2025-09-23 15:19:57
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Realizing high detectivity organic photodetectors in visible wavelength by doping highly ordered polymer PCPDTBT
摘要： A new method for realizing the response broadening of organic photodetectors (OPDs) using highly ordered polymer PCPDTBT doping has been proposed in this paper. The effects of PCPDTBT doping on the optical and electrical properties of OPDs were investigated experimentally. It was found that when the mass ratio of PTB7:PCPDTBT:PC61BM was 8.5:1.5:15, the response spectrum of the OPDs was broadened to 380–830 nm. The responsivity (R) and external quantum efficiency (EQE) of the OPDs reached 396, 244, 189 mA/W and 78%, 57%, 51% under 630, 530 and 460 nm illumination and (cid:0) 1 V bias, respectively, and the detectivity (D*) reached 1011 Jones. The results showed that the addition of PCPDTBT to PTB7:PC61BM increased the absorption of light at 700–830 nm. At the same time, the addition of PCPDTBT promotes the exciton dissociation interface in the active layer from the original one to the current three, they are PTB7:PCPDTBT, PTB7:PC61BM and PCPDTBT:PC61BM, which increase the probability of exciton dissociation in the active layer. In addition, the addition of highly ordered polymer PCPDTBT promotes the crystallization of the film and optimizes the carrier transport of the film. These synergistic effects promote the photocurrent of the OPDs.
关键词： Ternary bulk heterojunction,Exciton dissociation,Organic photodetectors,Microscopic morphology
更新于2025-09-23 15:19:57
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Highly sensitive, broadband, fast response organic photodetectors based on semi-tandem structure
摘要： Solution-processed organic photodetectors (OPDs) simultaneously integrating high performance by solution-processability. The semi-tandem structure directly superimposes two active layers with complementary absorption spectra, achieving a broad spectral response of 300-1000 nm. It provides a detection covering from ultraviolet to near-infrared range, while the external quantum efficiency in the spectral range of 550 nm to 950 nm retains 70 %. The high electron and hole injection barriers enable a dark current density as low as 6.51×10-5 mA cm-2 at -0.1 V, resulting in a noise current of 3.91×10-13 A Hz-1/2 at 70 Hz, which is nearly three times lower than single-junction photodetectors. Encouragingly, the device response speed is improved by suppressing the resistance-capacitance time constant of the device employing semi-tandem structure induced capacitance decreasing. The state-of-the-art OPDs contribute to the response time of 26.27 ns, which is the fastest one in OPDs to the best of our knowledge. We believe that the semi-tandem structures provide a new approach to achieving high-performance photodetectors integrating fast, sensitive and broadband response.
关键词： broadband,ultra-fast response,Organic photodetectors,semi-tandem structure
更新于2025-09-23 15:19:57
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High Sensitivity Visible-Near Infrared Organic Photodetector Based on Non-fullerene Acceptor
摘要： Highly sensitive solution-processed organic photodetectors (OPDs) with a broadband response ranging from visible to near infrared (NIR) and excellent overall device performance are demonstrated. The OPDs were fabricated from a blend consisting of a wide bandgap polymer donor and a newly developed fused octacylic small-molecule electron acceptor with acceptor–donor–acceptor structure, which shows relatively high and balanced hole/electron mobility and allow for thicker photoactive layer (~300 nm). In conjunction with the use of an optimized inverted device structure, the dark current density of the OPDs was suppressed to an ultralow level of (8.3±5.5)×10-10A cm-2 at bias of –1 V and the capability to directly weak light intensity is down to 0.24 pW cm?2, both are among the lowest reported values for OPDs. Owing to the low shot noise enabled by the inverted structure and the low thermal noise due to the high shunt resistance of the device, the obtained OPDs shows spectrally flat photoresponse in the range of 350–950 nm (UV-Vis-NIR) and a maximal specific detectivity (D*) of (2.1±0.1)×1013 Jones at 800–900 nm, which is among the best results of NIR OPDs reported to date and represents a highly sensitive photodetector for weak optical signal detection. Besides, the OPDs shows a wide bandwidth of 30 kHz, fast temporal response time around 12 us ~14 us and a large linear dynamic range of 106 dB.
关键词： dark current density,specific detectivity,non-fullerene acceptors,weak optical signal detection,organic photodetectors
更新于2025-09-23 15:19:57
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Incorporating Aluminum Plasmonic Nanohemisphere Arrays into Organic Ultraviolet Photodetectors for Improved Photoresponse
摘要： Aluminum nanostructures, which support surface plasmon resonances in the UV spectral range, were incorporated into conventional organic UV photodetectors with a structure of indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/poly(9,9-dioctyl?uorene-alt-bithiophene) (F8T2):[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM)/LiF/Al. Nanohemisphere arrays (NHSAs) were imprinted into the top surface of the soft organic active layer, thus transferring the pattern to the subsequently thermally deposited layers of LiF and Al. NHSA-top devices and ?at-top control devices were investigated by 3-dimensional ?nite-di?erence time-domain (3D-FDTD) electromagnetic simulations. Improved UV active layer absorbance and enhanced electric ?elds in the nanohemispheric region at the top of the active layer were shown for devices with the NHSA-top. The impact of the NHSA-top was found to be more signi?cant for devices with thin active layers and to gradually decrease with increasing active layer thickness. Fabricated NHSA-top devices with thin active layers exhibited improved photoresponse in terms of external quantum e?ciency, speci?c detectivity and on?o? response speed compared to ?at-top devices under 330 nm illumination and 0 to ?1 V bias. The method developed in this work provides a versatile and e?ective way to incorporate plasmonic nanostructures into optoelectronic devices to enhance device performance.
关键词： enhanced photoresponse,aluminum plasmonic nanostructures,organic photodetectors,nanoimprinting,ultraviolet photodetectors
更新于2025-09-19 17:13:59
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Enhanced photocurrent in organic photodetectors by the tunneling effect of a hafnium oxide thin film as an electron blocking layer
摘要： To achieve high detectivity of organic photodetectors (OPDs), we investigated hafnium oxide (HfO2) as an electron blocking layer in an attempt to obtain a low leakage current and high photocurrent by the tunneling effect. The prepared devices consisted of indium tin oxide (ITO)/HfO2/(poly(3-hexylthiophene-2,5-diyl)[P3HT]:PC60BM)/Yb/Al. To explore the tunneling effect in a hafnium oxide thin film, we fabricated a thin film using successive ionic layer deposition. The results for hafnium oxide were compared with those for aluminum oxide and poly(3,4-ethylenedioxythiophene)poly(styrenesulfonate) (PEDOT:PSS). We found that hafnium oxide results in a low leakage current and high photocurrent owing to the tunneling effect in the OPDs. The resulting detectivity of 1.76 × 1012 Jones for a film thickness of 5.5 nm and bandwidth of ～100 kHz is suitable for commercialization.
关键词： detectivity,tunneling effect,organic photodetectors,hafnium oxide,electron blocking layer
更新于2025-09-16 10:30:52
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P3HT-based visible-light organic photodetectors using PEI/PAA multilayers as a p-type buffer layer
摘要： A low leakage current is critical for achieving organic photodetectors (OPDs) with high detectivity. The insertion of buffer layers is an effective approach for reducing the reverse-biased leakage current. In this study, polyelectrolyte multilayers comprising polyethyleneimine (PEI) and polyacrylic acid (PAA) were introduced by a spin-assisted layer-by-layer technique into an OPD as a p-type buffer layer. Although PEI/PAA multilayers are insulators, when used as a buffer layer in our device, they suppressed the leakage current and also provided a high photocurrent due to the light-assisted tunneling effect. The prepared device configuration was ITO/(PEI/PAA)2/P3HT:PC60BM/Yb/Al. The performances of the OPDs were investigated by measuring the current–voltage characteristics, external quantum efficiency, and transient photocurrent. In addition, the operating mechanism of the OPDs was confirmed by impedance analysis. The device comprising (PEI/PAA)2 showed a specific detectivity of 3.11 × 1012 Jones and a bandwidth of 103.2 kHz at ?1 V and 525 nm. This performance is a numerical value that can be used in devices such as a line scan camera. In addition, because this device is fabricated by a low-temperature solution process, flexible and large-area substrates can be used.
关键词： light-assisted tunneling effect,organic photodetectors,PEI/PAA multilayers,p-type buffer layer,low-temperature solution process
更新于2025-09-16 10:30:52
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Exploiting supramolecular assemblies for filterless ultra-narrowband organic photodetectors with inkjet fabrication capability
摘要： Narrowband photodetectors are useful for a myriad of applications involving color discrimination as well as biological imaging and machine vision. Prevalent devices use broadband light absorbing materials in conjunction with electric (charge collection narrowing, photo multiplication) and optical strategies (optical cavity) to narrow down the spectral response of the detector. Here we exploit the intrinsic narrow absorption width of B13–50 nm peculiar to J-aggregates of strongly coupled cyanine dye molecules for narrowband photodetectors. Albeit using ultrathin J-aggregate films (10 nm) unparalleled optical aggregate properties lead to high external quantum efficiency (15%) and response speed (15 kHz) at low bias voltage ((cid:2)1 V). We show that the self-assembly process and device architecture used permit the incorporation of J-aggregates of various cyanine dyes with photodetection maxima ranging from the visible to the near-infrared region up to 1000 nm. Narrow bandwidth (o50 nm) photodetectors fabricated by inkjet printing the active device layers including the J-aggregate film perform on par with spin-coated devices, thus underlining their industrial potential.
关键词： J-aggregates,organic photodetectors,cyanine dyes,narrowband photodetectors,inkjet printing
更新于2025-09-12 10:27:22