The low temperature photoluminescence under bias (PLb) and the photoconductivity (PC) of a p-i-n GaInNAs/GaAs multiple quantum well sample have been investigated. Under optical excitation with photons of energy greater than the GaAs bandgap, PC and PLb results show a number of step-like increases when the sample is reverse biased. The nature of these steps, which depends upon the temperature, exciting wavelength and intensity and the number of quantum wells (QWs) in the device, is explained in terms of thermionic emission and negative charge accumulation due to the low confinement of holes in GaInNAs QWs. At high temperature, thermal escape from the wells becomes much more dominant and the steps smear out.
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http://dx.doi.org/10.1186/1556-276X-7-539 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
Department of Applied Physics and Integrated Education Institute for Frontier Science and Technology (BK21 Four), Kyung Hee University, Yongin 17104, Korea.
One-dimensional (1D) vertical nitrides are highly attractive for light-emitting diode (LED) applications because they are useful for overcoming the drawbacks of conventional GaN planar structures. However, the internal quantum efficiency (IQE) of GaN multi-quantum-well (MQW) nanowire (NW) LEDs, typical 1D GaN structures, is still too low to replace standard planar LEDs. Here, we report a phenomenon of light amplification from core-shell InGaN/GaN NW LEDs by incorporating graphene quantum dots (GQDs).
View Article and Find Full Text PDFNanomaterials (Basel)
November 2024
Institute of Micro and Nano Electronics, Chavchavadze Ave. 13, Tbilisi 0179, Georgia.
Recently, geometry-induced quantum effects in a new quasi-1D system, or nanograting (NG) layers, were introduced and investigated. Dramatic changes in band structure and unconventional photoluminescence effects were found in silicon quantum wells with high-energy barriers. Nanograting metal-semiconductor junctions were fabricated and investigated.
View Article and Find Full Text PDFLangmuir
December 2024
School of Material Science and Chemical Engineering, Harbin University of Science and Technology, Harbin 150040, China.
It is proven through transmission electron microscope (TEM) analysis that solar sensitizer CuSnS (CTS) dots prepared via the hot-injection route are nonspherical, polyhedral nanocrystals with the size of ∼11 nm. CTS dots were deposited into a porous TiO layer to form CTS/TiO, an effective type II heterojunction in photoanodes. The electronic and energy band structures of TiO and CTS were studied by the plane-wave ultrasoft pseudopotential method based on density functional theory (DFT) and verified by ultraviolet-visible (UV-vis) spectroscopy.
View Article and Find Full Text PDFJ Colloid Interface Sci
February 2025
State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, School of Chemistry and Chemical Engineering, Ningxia University, Yinchuan, Ningxia 750021, PR China. Electronic address:
The solar-driven photoelectrochemical desalination (SD-PED) technology, as a new emerging desalination technique, has been developed and attracted the increasing attention. However, practical application remains hampered by several constraints, including the rapid deterioration of photocurrent, and the long-term stability of system. In this research, MOF-derived nitrogen-doped carbon@CoO/BVO (CoO@NC/BVO) heterostructured photoanode was design for efficient and durable solar driven redox desalination.
View Article and Find Full Text PDFForensic Sci Int
December 2024
Institute of Physics, University of Brasília, Campus Universitário Darcy Ribeiro, Brasília, DF CEP: 70919-970, Brazil.
Carbon dots (CDs) are zero-dimensional carbon nanomaterials that have been subject of considerable interest due to their remarkable electronic and optical characteristics. Their adjustable properties have gathered attention in different fields, including biological sensing, drug delivery, photodynamic therapy, photocatalysis, solar cells, and latent fingerprint development. In forensic science, the frequently reported outstanding photoluminescence behavior and biocompatibility of CDs are particularly important.
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