Gallium nitride nanoparticles for solar-blind detectors

We investigate the properties of GaN semiconducting nanoparticles as a potential candidate for photodetection in the solar- blind region. The photocurrent spectral response is studied spanning the range 1·6-5·5 eV. A significant fraction of the response is in the range 4-5·5 eV. The results are compared to other optical properties and the origins of the features observed in the spectra are speculated upon

Library and information science journals on the UGC API list: A Study

76-92The University Grants Commission (UGC) has brought out API linked selection and promotion of teachers and other academic staff through the UGC Regulations 2010. It is also applied to the library staff at the level of Assistant librarian cadre and above and also college librarian. The UGC had made four amendments in the Regulations as quality measures in the past. The UGC recently identified and issued a list of 38652 journals for counting of API in the category of Research Publication - Journals for selection/promotion of teachers and other academic staff in the universities and colleges. The present study analyzes this list and identifies some issues with respect to the LIS journals

Library and information science journals on the UGC API list: A Study

The University Grants Commission (UGC) has brought out API linked selection and promotion of teachers and other academic staff through the UGC Regulations 2010. It is also applied to the library staff at the level of Assistant librarian cadre and above and also college librarian. The UGC had made four amendments in the Regulations as quality measure in the past. The UGC recently identified and issued a list of 38652 journals for counting of API in the category of Research Publication - Journals for selection/promotion of teachers and other academic staff in the university and colleges. The present study analyzes this list and identifies some issues with respect to the LIS journals

Gallium nitride nanoparticles for solar-blind detectors

We investigate the properties of GaN semiconducting nanoparticles as a potential candidate for photodetection in the solar-blind region. The photocurrent spectral response is studied spanning the range 1.6-5.5 eV. A significant fraction of the response is in the range 4-5.5 eV. The results are compared to other optical properties and the origins of the features observed in the spectra are speculated upon

Impact of Ligands on the Performance of PbS Quantum Dot Visible – Near - Infrared Photodetectors

Solution-processed lead sulfide quantum dots (PbS QDs) are an excellent candidate for photodetector applications because they exhibit broadband absorption, a wide range of tuneable bandgaps, high stability in air, and mechanical flexibility. However, a crucial criterion for the fabrication of high-performance photodetectors is the selection of the ligands, which can facilitate charge carrier transport between the PbS QDs and passivate the surface defects. In this work, the authors have studied the effect of traps on the performance of PbS QD photodetectors that are fabricated using different types of ligands, using intensity-dependent photoresponse dynamics. The best devices with lead halide ligands show a dark current density of 5 × 10−9 A cm−2 at −0.2 V, which is one of the lowest values reported thus far for solution-processed PbS QD-based photodetectors. Moreover, these devices show a high linear dynamic range (≈90 dB) and high detectivity (>1013 Jones), in addition to an f-3 dB of greater than 100 kHz without the application of an external voltage bias at a wavelength of 784 nm. These results suggest that with an appropriate selection of ligands, solution-processed photodetectors with a lower density of traps and a better device performance can be fabricated

Photocurrent imaging of phase segregation in a ternary polymer blend induced via a non-solvent route

Control of phase separation length scales of polymers in a solution-processed film of binary (two-component) polymer blends is the most important step to realize significant photocharge generation and transport efficiencies leading to efficient solar cells. The dynamics of phase segregation becomes more complex in ternary (three-component) polymer blends. In the three-component blend, one component serves as sensitizer, and other two act as donor and acceptor polymer. The sensitizer absorbs photons and the energy is quickly transferred to the host donor. Subsequently, efficient charge transfer occurs at the host donor/acceptor interface. Depending on the relative amount of phase segregation between sensitizer/donor, sensitizer/acceptor and donor/acceptor, the different photophysical mechanisms (viz. energy transfer and charge transfer) are either boosted or suppressed. The correct kind of morphology should allow efficient energy transfer at the sensitizer/donor interface followed by efficient charge transfer at the donor/acceptor interface. We attempt to address these requirements by modulating the nanomorphology of a ternary blend via tailoring the non-solvent concentration in the ternary polymer blend solution. Here, we study the effect of non-solvent mixing and resultant film morphology is characterized by wide-field local photocurrent imaging and photoluminescence imaging in a confocal microscope set-up

Blue perovskite light-emitting diodes: progress, challenges and future directions

Metal halide perovskites have excellent optical and electrical properties and can be easily processed via low-cost solution-based techniques like blade-coating and inkjet printing, promising a bright future for various optoelectronic applications. Recently, encouraging progress has been made in perovskite light-emitting diodes (PeLEDs). Green, red, and near-infrared PeLEDs have achieved high external quantum efficiencies of more than 20%. However, as historically blue electroluminescence remains challenging in all previous LED technologies, we are witnessing a similar case with the development of blue PeLEDs, an essential part of displays and solid-state lighting, which lag far behind those of their counterparts. Herein, we review the recent progress of blue PeLEDs and discuss the main challenges including colour instability, poor photoluminescence efficiency and emission quenching by interlayers. Future directions are provided to facilitate the development of efficient blue PeLEDs.Funding Agencies|ERC Starting Grant [717026]; Swedish Research Council [2016-05855]</p