Genome-wide identification of polyamine metabolism and ethylene synthesis genes in Chenopodium quinoa Willd. and their responses to low-temperature stress.

BACKGROUND: Quinoa (Chenopodium quinoa Willd.) is valued for its nutritional richness. However, pre-harvest sprouting poses a significant threat to yield and grain quality. This study aims to enhance our understanding of pre-harvest sprouting mitigation strategies, specifically through delayed sowing and avoiding rainy seasons during quinoa maturation. The overarching goal is to identify cold-resistant varieties and unravel the molecular mechanisms behind the low-temperature response of quinoa. We employed bioinformatics and genomics tools for a comprehensive genome-wide analysis of polyamines (PAs) and ethylene synthesis gene families in quinoa under low-temperature stress. RESULTS: This involved the identification of 37 PA biosynthesis and 30 PA catabolism genes, alongside 227 ethylene synthesis. Structural and phylogenetic analyses showcased conserved patterns, and subcellular localization predictions indicated diverse cellular distributions. The results indicate that the PA metabolism of quinoa is closely linked to ethylene synthesis, with multiple genes showing an upregulation in response to cold stress. However, differential expression within gene families suggests a nuanced regulatory network. CONCLUSIONS: Overall, this study contributes valuable insights for the functional characterization of the PA metabolism and ethylene synthesis of quinoa, which emphasize their roles in plant low-temperature tolerance and providing a foundation for future research in this domain.

Nickel Oxide Hole Injection Layers for Balanced Charge Injection in Quantum Dot Light-Emitting Diodes.

Quantum dot (QD) light-emitting diodes (QLEDs) are promising for next-generation displays, but suffer from carrier imbalance arising from lower hole injection compared to electron injection. A defect engineering strategy is reported to tackle transport limitations in nickel oxide-based inorganic hole-injection layers (HILs) and find that hole injection is able to enhance in high-performance InP QLEDs using the newly designed material. Through optoelectronic simulations, how the electronic properties of NiOx affect hole injection efficiency into an InP QD layer, finding that efficient hole injection depends on lowering the hole injection barrier and enhancing the acceptor density of NiOx is explored. Li doping and oxygen enriching are identified as effective strategies to control intrinsic and extrinsic defects in NiOx, thereby increasing acceptor density, as evidenced by density functional theory calculations and experimental validation. With fine-tuned inorganic HIL, InP QLEDs exhibit a luminance of 45 200 cd m-2 and an external quantum efficiency of 19.9%, surpassing previous inorganic HIL-based QLEDs. This study provides a path to designing inorganic materials for more efficient and sustainable lighting and display technologies.

Afferent renal denervation attenuates sympathetic over activation from the paraventricular nucleus in spontaneously hypertensive rats.

The effectiveness of Renal Denervation (RDN) in reducing blood pressure and systemic sympathetic activity in hypertensive patients has been established. However, the underlying central mechanism remains unknown. This study aimed to investigate the role of RDN in regulating cardiovascular function via the central Renin-Angiotensin System (RAS) pathway. Ten-week-old Spontaneously Hypertensive Rats (SHR) were subjected to Selective Afferent Renal Denervation (ADN) using capsaicin solution. We hypothesized that ADN would effectively reduce blood pressure and rebalance the RAS component of PVN in SHR. The experimental results show that ADN group exhibited significantly lower blood pressure, reduced systemic sympathetic activity, decreased chronic neuronal activation marker C-FOS expression in the paraventricular nucleus of hypothalamus (PVN), and improved arterial baroreflex function, compared with the Sham group. Furthermore, ACE and AT1 protein expression was reduced while ACE2 and MAS protein expression was increased in the PVN of SHR after ADN. These findings suggest that RDN may exert these beneficial effects through modulating the central RAS pathway.

Optimizing nitrogen application position to change root distribution in soil and regulate maize growth and yield formation in a wide-narrow row cropping system: pot and field experiments.

The wide-and narrow-row cropping technology used for maize has the advantages of protecting cultivated soil and improving the population structure in maize fields. However, the relationship between nitrogen application position and root interactions has not been determined. Through pot and field experiments, we evaluated the effects of two nitrogen application positions ((narrow row nitrogen application (RC) and wide row nitrogen application (RN)) and two nitrogen application regimens ((high nitrogen(HN) and low nitrogen(LN)) on root growth and yield composition of wide-narrow row maize during the flowering and harvest stages. In field experiments, RC increased the biomass, length and surface area of competing roots (narrow-row roots, CR) at the flowering stage. The yield and agronomic efficiency of N(AEN) and partial factor productivity of N(PFPN) were increased by RN compared to RC under HN, However, the AEN under LN was significantly lower; There was no significant effect on maize growth and biomass allocation at the same level of application of N. At the flowering stage, the results of CR and non-competing roots (wide-row roots, NCR) was consistent under pot experiments and the field experiments, and the yield under RN was also higher than that under RC, although the difference was not significant. Furthermore, according to the principal component analysis and correlation analysis, the competing roots were the main factor influencing yield and AEN. In conclusion, our study showed that RN is a useful fertilization method to improve overall productivity. All in all, how roots coordinate neighbors and nitrogen spatial heterogeneity is a complex ecological process, and its trophic behavior deserves further study.

Sub-Second Long Lifetime Triplet Exciton Reservoir for Highly Efficient and Stable Organic Light-Emitting Diode.

In organic light-emitting diode (OLED), achieving high efficiency requires effective triplet exciton confinement by carrier-transporting materials, which typically have higher triplet energy (ET) than the emitter, leading to poor stability. Here, an electron-transporting material (ETM), whose ET is 0.32 eV lower than that of the emitter is reported. In devices, it surprisingly exhibits strong confinement effect and generates excellent efficiency. Additionally, the device operational lifetime is 4.9 times longer than the device with a standard ETM, 1,3,5-tri(1-phenyl-1H-benzo[d]imidazol-2-yl) phenyl (whose ET 0.36 eV is higher than the emitter). This anomalous finding is ascribed to the exceptionally long triplet state lifetime (≈0.2 s) of the ETM. It is named as long-lifetime triplet exciton reservoir effect. The systematic analysis reveals that the long triplet lifetime of ETM can compensate the requirement for high ET with the help of endothermic energy transfer. Such combination of low ET and long lifetime provides equivalent exciton confinement effect and high molecular stability simultaneously. It offers a novel molecular design paradigm for breaking the dilemma between high efficiency and prolonged operational lifetime in OLEDs.

Dicarboxylic Acid-Assisted Surface Oxide Removal and Passivation of Indium Antimonide Colloidal Quantum Dots for Short-Wave Infrared Photodetectors.

Heavy-metal-free III-V colloidal quantum dots (CQDs) are promising materials for solution-processed short-wave infrared (SWIR) photodetectors. Recent progress in the synthesis of indium antimonide (InSb) CQDs with sizes smaller than the Bohr exciton radius enables quantum-size effect tuning of the band gap. However, it has been challenging to achieve uniform InSb CQDs with band gaps below 0.9 eV, as well as to control the surface chemistry of these large-diameter CQDs. This has, to date, limited the development of InSb CQD photodetectors that are sensitive to ≥ ${\ge }$ 1400 nm light. Here we adopt solvent engineering to facilitate a diffusion-limited growth regime, leading to uniform CQDs with a band gap of 0.89 eV. We then develop a CQD surface reconstruction strategy that employs a dicarboxylic acid to selectively remove the native In/Sb oxides, and enables a carboxylate-halide co-passivation with the subsequent halide ligand exchange. We find that this strategy reduces trap density by half compared to controls, and enables electronic coupling among CQDs. Photodetectors made using the tailored CQDs achieve an external quantum efficiency of 25 % at 1400 nm, the highest among III-V CQD photodetectors in this spectral region.

Accurate nowcasting of cloud cover at solar photovoltaic plants using geostationary satellite images.

Accurate nowcasting for cloud fraction is still intractable challenge for stable solar photovoltaic electricity generation. By combining continuous radiance images measured by geostationary satellite and an advanced recurrent neural network, we develop a nowcasting algorithm for predicting cloud fraction at the leading time of 0-4 h at photovoltaic plants. Based on this algorithm, a cyclically updated prediction system is also established and tested at five photovoltaic plants and several stations with cloud fraction observations in China. The results demonstrate that the cloud fraction nowcasting is efficient, high quality and adaptable. Particularly, it shows an excellent forecast performance within the first 2-hour leading time, with an average correlation coefficient close to 0.8 between the predicted clear sky ratio and actual power generation at photovoltaic plants. Our findings highlight the benefits and potential of this technique to improve the competitiveness of solar photovoltaic energy in electricity market.

Arresting Ion Migration from the ETL Increases Stability in Infrared Light Detectors Based on III-V Colloidal Quantum Dots.

III-V colloidal quantum dots (CQDs) are of interest in infrared photodetection, and recent developments in CQDs synthesis and surface engineering have improved performance. Here this work investigates photodetector stability, finding that the diffusion of zinc ions from charge transport layers (CTLs) into the CQDs active layer increases trap density therein, leading to rapid and irreversible performance loss during operation. In an effort to prevent this, this work introduces organic blocking layers between the CQDs and ZnO layers; but these negatively impact device performance. The device is then, allowing to use a C60:BCP as top electron-transport layer (ETL) for good morphology and process compatibility, and selecting NiOX as the bottom hole-transport layer (HTL). The first round of NiOX -based devices show efficient light response but suffer from high leakage current and a low open-circuit voltage (Voc) due to pinholes. This work introduces poly[bis(4-phenyl) (2,4,6-trimethylphenyl)amine] (PTAA) with NiOX NC to form a hybrid HTL, an addition that reduces pinhole formation, interfacial trap density, and bimolecular recombination, enhancing carrier harvesting. The photodetectors achieve 53% external quantum efficiency (EQE) at 970 nm at 1 V applied bias, and they maintain 95% of initial performance after 19 h of continuous illuminated operation. The photodetectors retain over 80% of performance after 80 days of shelf storage.

Molecular surface programming of rectifying junctions between InAs colloidal quantum dot solids.

Heavy-metal-free III-V colloidal quantum dots (CQDs) show promise in optoelectronics: Recent advancements in the synthesis of large-diameter indium arsenide (InAs) CQDs provide access to short-wave infrared (IR) wavelengths for three-dimensional ranging and imaging. In early studies, however, we were unable to achieve a rectifying photodiode using CQDs and molybdenum oxide/polymer hole transport layers, as the shallow valence bandedge (5.0 eV) was misaligned with the ionization potentials of the widely used transport layers. This occurred when increasing CQD diameter to decrease the bandgap below 1.1 eV. Here, we develop a rectifying junction among InAs CQD layers, where we use molecular surface modifiers to tune the energy levels of InAs CQDs electrostatically. Previously developed bifunctional dithiol ligands, established for II-VI and IV-VI CQDs, exhibit slow reaction kinetics with III-V surfaces, causing the exchange to fail. We study carboxylate and thiolate binding groups, united with electron-donating free end groups, that shift upward the valence bandedge of InAs CQDs, producing valence band energies as shallow as 4.8 eV. Photophysical studies combined with density functional theory show that carboxylate-based passivants participate in strong bidentate bridging with both In and As on the CQD surface. The tuned CQD layer incorporated into a photodiode structure achieves improved performance with EQE (external quantum efficiency) of 35% (>1 µm) and dark current density < 400 nA cm-2, a >25% increase in EQE and >90% reduced dark current density compared to the reference device. This work represents an advance over previous III-V CQD short-wavelength IR photodetectors (EQE < 5%, dark current > 10,000 nA cm-2).

Self-assembled monolayer-based blue perovskite LEDs.

Blue perovskite light-emitting diodes (LEDs) have shown external quantum efficiencies (EQEs) of more than 10%; however, devices that emit in the true blue-those that accord with the emission wavelength required for Rec. 2100 primary blue-have so far been limited to EQEs of ~6%. We focused here on true blue emitting CsPbBr3 colloidal nanocrystals (c-NCs), finding in early studies that they suffer from a high charge injection barrier, a problem exacerbated in films containing multiple layers of nanocrystals. We introduce a self-assembled monolayer (SAM) active layer that improves charge injection. We identified a bifunctional capping ligand that simultaneously enables the self-assembly of CsPbBr3 c-NCs while passivating surface traps. We report, as a result, SAM-based LEDs exhibit a champion EQE of ~12% [CIE of (0.132, 0.069) at 4.0 V with a luminance of 11 cd/m2], and 10-fold-enhanced operating stability relative to the best previously reported Rec. 2100-blue perovskite LEDs.

Halide-Driven Synthetic Control of InSb Colloidal Quantum Dots Enables Short-Wave Infrared Photodetectors.

In the III-V family of colloidal quantum dot (CQD) semiconductors, InSb promises access to a wider range of infrared wavelengths compared to many light-sensing material candidates. However, achieving the necessary size, size-dispersity, and optical properties has been challenging. Here the synthetic challenges associated with InSb CQDs are investigated and it is found that uncontrolled reduction of the antimony precursor hampers the controlled growth of CQDs. To overcome this, a synthetic strategy that combines nonpyrophoric precursors with zinc halide additives is developed. The experimental and computational studies show that zinc halide additives decelerate the reduction of the antimony precursor, facilitating the growth of more uniformly sized CQDs. It is also found that the halide choice provides additional control over the strength of this effect. The resultant CQDs exhibit well-defined excitonic transitions in spectral range of 1.26-0.98 eV, along with strong photoluminescence. By implementing a postsynthesis ligand exchange, colloidally stable inks enabling the fabrication of high-quality CQD films are achieved. The first demonstration of InSb CQD photodetectors is presented reaching 75% external quantum efficiency (QE) at 1200 nm, to the knowledge the highest short-wave infrared (SWIR) QE reported among heavy-metal-free infrared CQD-based devices.

Case Report: Semi-Ex Vivo Hepatectomy Combined with Autologous Liver Transplantation for Alveolar Echinococcosis in Children.

Hepatic alveolar echinococcosis (AE) is a zoonotic disease caused by the metacestode of Echinococcus multilocularis. Although surgical resection is the optimal treatment for hepatic AE, some patients with hepatic AE located in special introhepatic sites cannot be radically cured by conventional surgery. Here, we report that a 10-year-old female patient was admitted to the hospital with occupying liver lesions for 6 months. Computed tomography examination showed irregular mixed-density masses in the right lobe and caudate lobe of the liver, with partial invasion of the right hepatic artery, right hepatic vein, and right branch of the portal vein. The patient was preoperatively diagnosed with hepatic AE, which cannot be cured by conventional liver lobectomy. The patient underwent semi-ex vivo liver resection with autologous liver transplantation (second hepatic portal reconstruction, posterior hepatic inferior vena cava repair, and hepatic artery repair) and biliary-intestinal anastomosis. After hospital discharge, she has kept living a healthy life without disease recurrence for 13 months until the end of the last follow-up. This case shows that semi-ex vivo hepatectomy with autologous liver transplantation might be a feasible and safe choice for certain patients with AE located in special introhepatic sites, which has provided novel experiences for the surgical treatment of hepatic AE.

Control over Charge Carrier Mobility in the Hole Transport Layer Enables Fast Colloidal Quantum Dot Infrared Photodetectors.

Solution-processed colloidal quantum dots (CQDs) are promising materials for photodetectors operating in the short-wavelength infrared region (SWIR). Devices typically rely on CQD-based hole transport layers (HTL), such as CQDs treated using 1,2-ethanedithiol. Herein, we find that these HTL materials exhibit low carrier mobility, limiting the photodiode response speed. We develop instead inverted (p-i-n) SWIR photodetectors operating at 1370 nm, employing NiOx as the HTL, ultimately enabling 4× shorter fall times in photodiodes (∼800 ns for EDT and ∼200 ns for NiOx). Optoelectronic simulations reveal that the high carrier mobility of NiOx enhances the electric field in the active layer, decreasing the overall transport time and increasing photodetector response time.

Sequential Co-Passivation in InAs Colloidal Quantum Dot Solids Enables Efficient Near-Infrared Photodetectors.

III-V colloidal quantum dots (CQDs) are promising materials for optoelectronic applications, for they avoid heavy metals while achieving absorption spanning the visible to the infrared (IR). However, the covalent nature of III-V CQDs requires the development of new passivation strategies to fabricate conductive CQD solids for optoelectronics: this work shows herein that ligand exchanges, previously developed in II-VI and IV-VI quantum dots and employing a single ligand, do not fully passivate CQDs, and that this curtails device efficiency. Guided by density functional theory (DFT) simulations, this work develops a co-passivation strategy to fabricate indium arsenide CQD photodetectors, an approach that employs the combination of X-type methyl ammonium acetate (MaAc) and Z-type ligands InBr3 . This approach maintains charge carrier mobility and improves passivation, seen in a 25% decrease in Stokes shift, a fourfold reduction in the rate of first-exciton absorption linewidth broadening over time-under-stress, and leads to a doubling in photoluminescence (PL) lifetime. The resulting devices show 37% external quantum efficiency (EQE) at 950 nm, the highest value reported for InAs CQD photodetectors.

New insights into the mechanism of Fered-Fenton treatment of industrial wastewater with high chloride content: Role of multiple reactive species.

Hydroxyl radical (OH) is considered the dominant reactive species in the electro-Fenton (EF) and Fered-Fenton (EF-Fere) processes for wastewater treatment. However, in chloride-rich media, this is arguable due to the obscure mechanisms for the oxidant speciation and pollutant degradation. Herein, the role of active chlorine and Fe(IV)-oxo species (FeIVO2+) as primary oxidizing agents in HClO-mediated Fered-Fenton (EF-Fere-HClO) process is discussed, along with the dependence of their contribution on the pollutant structure. HClO generated from anodic oxidation of Cl- can be consumed by added H2O2 to form singlet oxygen (1O2), which is detrimental because this species is quickly deactivated by water. The reaction between HClO and Fe2+ was proved to generate FeIVO2+, rather than OH or Cl suggested in the literature. The yield of FeIVO2+ species was proportional to the Cl- concentration and barely affected by solution pH. The long-lived HClO and FeIVO2+ can selectively react with electron-rich compounds, which occurs simultaneously to the non-selective attack of OH formed from Fenton's reaction. The FeIVO2+ and OH concentration profiles were successfully modelled. Although the accumulation of toxic chlorinated by-products from HClO-mediated oxidation might cause new environmental concerns, the toxicity of pesticide wastewater with 508 mM Cl- was halved upon EF-Fere-HClO treatment.

Bifunctional Electron-Transporting Agent for Red Colloidal Quantum Dot Light-Emitting Diodes.

Indium phosphide (InP) quantum dots have enabled light-emitting diodes (LEDs) that are heavy-metal-free, narrow in emission linewidth, and physically flexible. However, ZnO/ZnMgO, the electron-transporting layer (ETL) in high-performance red InP/ZnSe/ZnS LEDs, suffers from high defect densities, quenches luminescence when deposited on InP, and induces performance degradation that arises due to trap migration from the ETL to the InP emitting layer. We posited that the formation of Zn2+ traps on the outer ZnS shell, combined with sulfur and oxygen vacancy migration between ZnO/ZnMgO and InP, may account for this issue. We synthesized therefore a bifunctional ETL (CNT2T, 3',3'″,3'″″-(1,3,5-triazine-2,4,6-triyl)tris(([1,1'-biphenyl]-3-carbonitrile)) designed to passivate Zn2+ traps locally and in situ and to prevent vacancy migration between layers: the backbone of the small molecule ETL contains a triazine electron-withdrawing unit to ensure sufficient electron mobility (6 × 10-4 cm2 V-1 s-1), and the star-shaped structure with multiple cyano groups provides effective passivation of the ZnS surface. We report as a result red InP LEDs having an EQE of 15% and a luminance of over 12,000 cd m-2; this represents a record among organic-ETL-based red InP LEDs.

Knockdown of polypyrimidine tract binding protein facilitates motor function recovery after spinal cord injury.

After spinal cord injury (SCI), a fibroblast- and microglia-mediated fibrotic scar is formed in the lesion core, and a glial scar is formed around the fibrotic scar as a result of the activation and proliferation of astrocytes. Simultaneously, a large number of neurons are lost in the injured area. Regulating the dense glial scar and replenishing neurons in the injured area are essential for SCI repair. Polypyrimidine tract binding protein (PTB), known as an RNA-binding protein, plays a key role in neurogenesis. Here, we utilized short hairpin RNAs (shRNAs) and antisense oligonucleotides (ASOs) to knock down PTB expression. We found that reactive spinal astrocytes from mice were directly reprogrammed into motoneuron-like cells by PTB downregulation in vitro. In a mouse model of compression-induced SCI, adeno-associated viral shRNA-mediated PTB knockdown replenished motoneuron-like cells around the injured area. Basso Mouse Scale scores and forced swim, inclined plate, cold allodynia, and hot plate tests showed that PTB knockdown promoted motor function recovery in mice but did not improve sensory perception after SCI. Furthermore, ASO-mediated PTB knockdown improved motor function restoration by not only replenishing motoneuron-like cells around the injured area but also by modestly reducing the density of the glial scar without disrupting its overall structure. Together, these findings suggest that PTB knockdown may be a promising therapeutic strategy to promote motor function recovery during spinal cord repair.

A novel multi-scale 2D CNN with weighted focal loss for arrhythmias detection on varying-dimensional ECGs.

Objective. The ECG is a standard diagnostic tool for identifying many arrhythmias. Accurate diagnosis and early intervention for arrhythmias are of great significance to the prevention and treatment of cardiovascular disease. Our objective is to develop an algorithm that can automatically identify 30 arrhythmias by using varying-dimensional ECG signals.Approach. In this paper, we firstly proposed a novel multi-scale 2D CNN that can effectively capture pathological information from small-scale to large-scale from ECG signals to identify 30 arrhythmias from 12-lead, 6-lead, 4-lead, 3-lead, and 2-lead ECGs. Secondly, we explored the effects of varying convolution kernels sizes and branch subnetworks on the model's performance for each arrhythmia. Thirdly, we introduced the weighted focal loss to alleviate the positive-negative class imbalance problem in the multi-label arrhythmias classification. Fourthly, we explored the utility of reduced-lead ECGs in detecting arrhythmias by comparing the performances of models on varying-dimensional ECGs.Main results. As a follow-up entry after the PhysioNet/Computing in Cardiology Challenge (2021), our proposed approach achieved the official test scores of 0.52, 0.47, 0.53, 0.51, and 0.50 for the 12-lead, 6-lead, 4-lead, 3-lead, and 2-lead ECGs on the hidden test set (comparable to that of 6th, 11th, 4th, 5th, and 7th out of 39 teams in the Challenge).Significance. A multi-scale framework capable of detecting 30 arrhythmias from varying-dimensional ECGs was proposed in our work. We preliminarily verified that the multi-scale perception fields may be necessary to capture more comprehensive pathological information for arrhythmias detection. Besides, we also verified that the weighted focal loss may alleviate the positive-negative class imbalance and improve the model's generalization performance on the cross-dataset. In addition, we observed that some reduced-lead models, such as the 4-lead and 3-lead models, can even achieve performance that is almost comparable to that of the 12-lead model. The excellent performance of our proposed framework demonstrates its great potential in detecting a wide range of arrhythmias.

Single-channel EEG sleep staging based on data augmentation and cross-subject discrepancy alleviation.

Automatic sleep stage classification is an effective technology compared to conventional artificial visual inspection in the field of sleep staging. Numerous algorithms based on machine learning and deep learning on single-channel electroencephalogram (EEG) have been proposed in recent years, however, category imbalance and cross-subject discrepancy are still the main factors restricting the accuracy of existing methods. This study proposed an innovative end-to-end neural network to solve these problems, specifically, four data augmentation methods were designed to eliminate category imbalance, and domain adaptation modules were designed for the alignment of marginal distribution, conditional distribution, and channel and spatial level distribution of feature maps, as well as the capture of transferable regions on the feature maps using a transfer attention mechanism. We conducted experiments on two publicly available datasets (Sleep-EDF Database Expanded, 2013 and 2018 version), Cohen's kappa coefficient (k) of 0.77 (Fpz-Cz) and 0.73 (Pz-Oz) were realized on the Sleep-EDF-2013 dataset, and a k of 0.75 (Fpz-Cz) and 0.68 (Pz-Oz) were realized on the Sleep-EDF-2018 dataset. An experiment was also conducted on the dataset drawn from the 2018 Physionet challenge, which containing people with sleep disorders, and a performance improvement was still found. Our comparative experiments with similar studies showed that our model was superior to most other studies, indicating our proposed EEG data augmentation and domain adaptation based cross-subject discrepancy alleviation approach is effective to improve the performance of automatic sleep staging.

Electron-Transport Layers Employing Strongly Bound Ligands Enhance Stability in Colloidal Quantum Dot Infrared Photodetectors.

Solution-processed photodetectors based on colloidal quantum dots (CQDs) are promising candidates for short-wavelength infrared light sensing applications. Present-day CQD photodetectors employ a CQD active layer sandwiched between carrier-transport layers in which the electron-transport layer (ETL) is composed of metal oxides. Herein, a new class of ETLs is developed using n-type CQDs, finding that these benefit from quantum-size effect tuning of the band energies, as well as from surface ligand engineering. Photodetectors operating at 1450 nm are demonstrated using CQDs with tailored functionalities for each of the transport layers and the active layer. By optimizing the band alignment between the ETL and the active layer, CQD photodetectors that combine a low dark current of ≈1 × 10-3 mA cm-2 with a high external quantum efficiency of ≈66% at 1 V are reported, outperforming prior reports of CQD photodetectors operating at >1400 nm that rely on metal oxides as ETLs. It is shown that stable CQD photodetectors rely on well-passivated CQDs: for ETL CQDs, a strongly bound organic ligand trans-4-(trifluoromethyl)cinnamic acid (TFCA) provides improved passivation compared to the weakly bound inorganic ligand tetrabutylammonium iodide (TBAI). TFCA suppresses bias-induced ion migration inside the ETL and improves the operating stability of photodetectors by 50× compared to TBAI.