Organic-inorganic hybrid ultraviolet photodetectors with tunable spectral response are desirable for many different applications. In this work, we blended poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) with ZnO nanoparticles in weight ratios of 1 : 1 and 2 : 1 to create charge traps within the active layers for devices with the conventional structure ITO/PEDOT : PSS/PTAA : ZnO/BCP/Al. Thin (150-200 nm) and thick (1400-1900 nm) active layers were employed to utilize charge collection narrowing (CCN). Both thickness and composition of the active layer impacted the spectral tunability of the photoresponse. A single narrow response peak centered at 420 nm (the PTAA absorption edge) with a full width at half maximum of 12 nm was achieved from the device with a 1900 nm active layer and PTAA : ZnO weight ratio of 1 : 1. Decreasing the active layer thickness to 150 nm resulted in a broad spectral response between 320-420 nm with an external quantum efficiency (EQE) value of 295% under 350 nm illumination and a -1 V bias, exhibiting photomultiplication via charge trapping and injection even at small reverse biases. Increasing the weight ratio of PTAA : ZnO to 2 : 1 lowered both the dark current and photocurrent, eliminated photomultiplication in the thin device, and diminished the efficacy of CCN to narrow the spectral photoresponse in the thick device. Transfer matrix method (TMM) and 3-dimensional finite-difference time-domain (3D-FDTD) simulations were performed to understand the impact of thickness and composition of the active layer on the spectral response of UV photodetectors in terms of exciton generation rate and electric field distribution within the devices.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/c8cp00361k | DOI Listing |
Plant Cell Rep
January 2025
MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, Guangdong Provincial Key Laboratory of Laser Life Science, Guangzhou Key Laboratory of Spectral Analysis and Functional Probes, College of Biophotonics, School of Optoelectronic Science and Engineering, South China Normal University, Guangzhou, 510631, China.
The three SDEs of CLas were expressed in citrus leaves by AuNPs-PEI mediated transient expression system, and promoted the proliferation of CLas and inhibited citrus immunity. Huanglongbing (HLB) is the most severe bacterial disease of citrus caused by Candidatus Liberibacter asiaticus (CLas). CLas suppress host immune responses and promote infection by sec-dependent effectors (SDEs), thus insight into HLB pathogenesis is urgently needed to develop effective management strategies.
View Article and Find Full Text PDFEBioMedicine
January 2025
Institute of Immunology, Hannover Medical School, Hannover, Germany; Cluster of Excellence RESIST (EXC 2155), Hannover Medical School, Hannover, Germany; German Centre for Infection Research, Partner Site Hannover-Braunschweig, Hannover, Germany. Electronic address:
Background: Aging increases disease susceptibility and reduces vaccine responsiveness, highlighting the need to better understand the aging immune system and its clinical associations. Studying the human immune system, however, remains challenging due to its complexity and significant inter-individual variability.
Methods: We conducted an immune profiling study of 550 elderly participants (≥60 years) and 100 young controls (20-40 years) from the RESIST Senior Individuals (SI) cohort.
Bioinformatics
January 2025
Section of Bioinformatics, Division of Systems Medicine, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, W12 0NN, United Kingdom.
Unlabelled: Metabolomics extensively utilizes Nuclear Magnetic Resonance (NMR) spectroscopy due to its excellent reproducibility and high throughput. Both one-dimensional (1D) and two-dimensional (2D) NMR spectra provide crucial information for metabolite annotation and quantification, yet present complex overlapping patterns which may require sophisticated machine learning algorithms to decipher. Unfortunately, the limited availability of labeled spectra can hamper application of machine learning, especially deep learning algorithms which require large amounts of labelled data.
View Article and Find Full Text PDFBiomed Tech (Berl)
December 2024
66284 School of Design & Art, Shenyang Aerospace University, Shenyang, China.
Objectives: The actions and decisions of pilots are directly related to aviation safety. Therefore, understanding the neurological and cognitive processes of pilots during flight is essential. This study aims to investigate the EEG signals of pilots to understand the characteristic changes during the climb and descent stages of flight.
View Article and Find Full Text PDFSensors (Basel)
January 2025
European Southern Observatory, Santiago 7630000, Chile.
The most widely used radiance sensor for monitoring Night Sky Brightness (NSB) is the Sky Quality Meter (SQM), making its measurement stability fundamental. A method using the Sun as a calibrator was applied to analyse the quality of the measures recorded in the Veneto Region (Italy) and at La Silla (Chile). The analysis mainly revealed a tendency toward reductions in measured NSB due to both instrument ageing and atmospheric variations.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!