An Electric Bus with a Battery Exchange System

As part of the ongoing effort to be independent of petroleum resources and to be free from pollutant emission issues, various electric vehicles have been developed and tested through their integration with real world systems. In the current paper, yet another application specific EV for public transportation, an electric bus, is introduced and explained with results from the pilot test program which was carried out under real traffic conditions. The main feature of the current system is a battery exchanging mechanism mounted on the roof of the bus. The current configuration certainly requires an externally fabricated battery exchanging robot system that would complement the electric bus for a fully automated battery exchanging process. The major advantage of the current system is the quick re-charging of the electric energy through the physical battery exchange and the possible utilization of the battery exchange station as a mini scale energy storage system for grid system peak power shaving. With the total system solution approach for the public transportation system, it is fully expected to create outstanding business opportunities in number of areas such as battery suppliers, battery exchanging station management, battery leasing and many more

Enhancement of photoresponsive electrical characteristics of multilayer MoS2 transistors using rubrene patches

Multilayer MoS2 is a promising active material for sensing, energy harvesting, and optoelectronic devices owing to its intriguing tunable electronic band structure. However, its optoelectronic applications have been limited due to its indirect band gap nature. In this study, we fabricated a new type of phototransistor using multilayer MoS2 crystal hybridized with p-type organic semiconducting rubrene patches. Owing to the outstanding photophysical properties of rubrene, the device characteristics such as charge mobility and photoresponsivity were considerably enhanced to an extent depending on the thickness of the rubrene patches. The enhanced photoresponsive conductance was analyzed in terms of the charge transfer doping effect, validated by the results of the nanoscale laser confocal microscope photoluminescence (PL) and time-resolved PL measurements.[Figure not available: see fulltext.] © 2015, Tsinghua University Press and Springer-Verlag Berlin Heidelberg112141sciescopu

Luminescent Sm-doped aluminosilicate glass as a substrate for enhanced photoresponsivity of MoS2 based photodetector

© 2021 Elsevier B.V.The choice of substrate is crucial for device applications, in particular for atomically thin materials such as monolayer transition metal dichalcogenides. The interaction between the active material and the substrate could be exploited to improve the device performance. In this work, we used a Sm-doped aluminosilicate glass (Sm-ASG) as a substrate for monolayer MoS2 based photodetector. Due to the strong high-energy emission lines of Sm, Sm-ASG substrate absorbs the incident light and acts as second excitation source compensating the low absorption of the MoS2 monolayer. On Sm-ASG substrate, the MoS2 photoresponsivity was increased up to 13,157 AW−1 as compared to 5,740 AW−1 on undoped ASG substrate, under illumination of a monochromatic laser with 520 nm wavelength at a power of 0.2 µW. The significantly enhanced photoresponse, which is amongst the highest reported values for unbiased photoconductors, is attributed to the dual function of Sm-ASG substrate, consisting of a surface charge transfer and an enhanced photoexcitation via a photon recycling effect. Our new approach, based on the simple use of substrate, paves the way for achieving high performance optoelectronic devices.11Nsciescopu

Anomalous Temperature and Polarization Dependences of Photoluminescence of Metal-Organic Chemical Vapor Deposition-Grown GeSe2

Germanium diselenide (GeSe2) is a 2D semiconductor with air stability, a wide bandgap, and anisotropic optical properties. The absorption and photoluminescence (PL) of single-crystalline 2D GeSe2 grown by metal-organic chemical vapor deposition and their dependence on temperature and polarization are studied. The PL spectra exhibit peaks at 2.5 eV (peak A) and 1.8 eV (peak B); peak A displays a strongly polarized emission along the short axis of the crystal, and peak B displays a weak polarization perpendicular to that of peak A. With increasing temperature, peak B shows anomalous behaviors, i.e., an increasing PL energy and intensity. The excitation energy-dependent PL, time-resolved PL, and density functional theory calculations suggest that peak A corresponds to the band-edge transition, whereas peak B originates from the inter-band mid-gap states caused by selenium vacancies passivated by oxygen atoms. The comprehensive study on the PL of single-crystalline GeSe2 sheds light on the origins of light emission in terms of the band structure of anisotropic GeSe2, making it beneficial for the corresponding optoelectronic applications