Snehasis Sahoo

National Tsing Hua University

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Jwo‐Huei Jou

National Tsing Hua University

K. R. Justin Thomas

Indian Institute of Technology Roorkee

Deepak Kumar Dubey

First Solar (United States)

Meenu Singh

National Tsing Hua University

Vellaichamy Joseph

National Central University

Rajendra Kumar Konidena

SRM Institute of Science and Technology

Ching‐Wu Wang

National Chung Cheng University

Saulius Grigalevičius

Kaunas University of Technology

Zhe-Kai He

National Tsing Hua University

Sudhir Kumar

ETH Zurich

Cooperative Institutions

National Tsing Hua University

National Taiwan University

Sardar Patel University

Indian Institute of Technology Roorkee

Kaunas University of Technology

National Yang Ming Chiao Tung University

Bhabha Atomic Research Centre

National Sun Yat-sen University

Research Center for Applied Science, Academia Sinica

National Hsinchu University of Education

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

A new molecular design based on hybridized local and charge transfer fluorescence for highly efficient (>6%) deep-blue organic light emitting diodes

Chemical Communications (2017)

Rajendra Kumar Konidena K. R. Justin Thomas Deepak Kumar Dubey Snehasis Sahoo Jwo‐Huei Jou

A new molecular design featuring a carbazole-derivative as an acceptor and a triphenylamine donor and displaying hybridized local and charge transfer (HLCT) fluorescence is demonstrated.

Deep blue

10.1039/c7cc07139f

Cite

Citations (79)

Highly efficient deep-blue OLED with a novel carbazole based florescent emitter

Extended Abstracts of the 2020 International Conference on Solid State Devices and Materials (2017)

Snehasis Sahoo Mohua Singh V. Joseph K. R. Justin Thomas Jwo‐Huei Jou

Carbazole

10.7567/ssdm.2017.f-6-04

Cite

Citations (0)

High light-quality OLEDs with a wet-processed single emissive layer

Scientific Reports (2018)

Meenu Singh Jwo‐Huei Jou Snehasis Sahoo S. Sujith Zhe-Kai He

Abstract High light-quality and low color temperature are crucial to justify a comfortable healthy illumination. Wet-process enables electronic devices cost-effective fabrication feasibility. We present herein low color temperature, blue-emission hazards free organic light emitting diodes (OLEDs) with very-high light-quality indices, that with a single emissive layer spin-coated with multiple blackbody-radiation complementary dyes, namely deep-red, yellow, green and sky-blue. Specifically, an OLED with a 1,854 K color temperature showed a color rendering index (CRI) of 90 and a spectrum resemblance index (SRI) of 88, whose melatonin suppression sensitivity is only 3% relative to a reference blue light of 480 nm. Its maximum retina permissible exposure limit is 3,454 seconds at 100 lx, 11, 10 and 6 times longer and safer than the counterparts of compact fluorescent lamp (5,920 K), light emitting diode (5,500 K) and OLED (5,000 K). By incorporating a co-host, tris(4-carbazoyl-9-ylphenyl)amine (TCTA), the resulting OLED showed a current efficiency of 24.9 cd/A and an external quantum efficiency of 24.5% at 100 cd/m 2 . It exhibited ultra-high light quality with a CRI of 93 and an SRI of 92. These prove blue-hazard free, high quality and healthy OLED to be fabrication feasible via the easy-to-apply wet-processed single emissive layer with multiple emitters.

Black-body radiation

Color rendering index

Color temperature

10.1038/s41598-018-24125-4

Cite

Citations (25)

Blue-Hazard-Free Organic Light-Emitting Diode with a Lifetime Greater than 200,000 h

Electronics (2023)

Jwo‐Huei Jou Wen-Jun Lin Sheng‐Hsu Shih Yi-Siang Wang Snehasis Sahoo

Blue-hazard-free lighting is in urgent need in order to protect human eyes and physiology. A candlelight-style organic light emitting diode (OLED) is so far the safest measure for its blue-hazard-free, low-color-temperature illumination. However, lifetime is still the most critical reliability issue in OLEDs, especially in lighting applications that are closely associated with high current density operation. Here, we present a novel approach to develop blue-hazard-free OLEDs with a lifetime exceeding 200,000 h at 1000 cd/m2 by employing a tandem structure with ultra-high purity emitter. The resultant device shows a current efficacy of 37.4 cd/A, an external quantum efficiency (EQE) of 22.7%, an 80 CRI, and a 78 SRI with a 223,500 h lifetime (t50). Additionally, the resultant device also exhibits a long retina exposure duration of 12,300 s (3.42 h) and suppresses very less melatonin generation (1.7%), demonstrating that the fabricated OLED device is a highly prospective general lighting source to safeguard human health.

Quantum Efficiency

10.3390/electronics12092099

Cite

Citations (1)

Simple carbazole based deep-blue emitters: The effect of spacer, linkage and end-capping cyano group on the photophysical and electroluminescent properties

Dyes and Pigments (2018)

Vellaichamy Joseph K. R. Justin Thomas Snehasis Sahoo Meenu Singh Jwo‐Huei Jou

Carbazole

Solvatochromism

Sonogashira coupling

Acetylene

Chromophore

Suzuki reaction

HOMO/LUMO

10.1016/j.dyepig.2017.12.061

Cite

Citations (14)

Approach for Designing Human-Centered and Energy Saving Lighting Luminaires

Photonics (2022)

Jwo‐Huei Jou Zhe-Kai He Deepak Kumar Dubey Yi-Fang Tsai Snehasis Sahoo

Electric light has been widely adopted in numerous applications, including signage, display, and illumination. Enhancing its efficiency and quality has been the focal point until now. Long exposure to intensive blue-light-enriched white light is, however, likely to cause health concerns, such as retina damage and melatonin suppression. A good light should hence be redefined as, at least, human-friendly, besides energy-saving and high-quality. Here, we demonstrate a novel design approach toward a good light based on the state-of-the-art solid-state lighting technologies. Taking the typical phosphor converted white-light-emitting diode (LED) for lighting, for example, a 2000 K orange-white emission with a black-body-radiation chromaticity can be 5 times safer than the 5000 K pure-white counterpart from a retina-protection perspective and 3.9 times safer from an MLT-secretion perspective. Further tuning its chromaticity from black-body-radiation- to sunlight-style, the 2000 K LED can be made 303% safer in terms of maximum retina permissible exposure limit or 100% better in terms of melatonin suppression sensitivity. Moreover, its corresponding efficacy limit can be increased from 270 to 285 lm/W, while keeping light quality constant at 91, in terms of natural light spectrum resemblance index. The same approach can be extended to organic LED as well as the design of a good light for display, wherein pure-white emission with a color temperature around 6000 K is suggested to replace the bluish-white backlight to safeguard human health.

Chromaticity

Backlight

Color temperature

Human eye

SAFER

10.3390/photonics9100726

Cite

Citations (6)

Development of Activated Carbon Using One Step Carbonization and Activation Reaction by Polymer Blend Method

International Letters of Chemistry Physics and Astronomy (2015)

S. Manocha Parth Joshi Amit Brahmbhatt Amiya Banerjee Snehasis Sahoo

In the present work, a one step carbon activation process was developed by stabilized poly-blend. It is carbonized in nitrogen atmosphere and activated in steam in one step for known interval of times to enhance the surface area and develop interconnected porosity. The weight-loss behavior during steam activation of stabilized poly-blend at different temperatures, surface area and pore size distribution were studied to identify the optimum synthesis parameters. The results of surface characteristics were compared with those of activated carbon prepared by carbonization and activation in two steps. It was found that activation temperature has profound effect on surface characteristics. As activation temperature was raised from 800 °C to 1150 °C, surface area of activated carbon increased about three times. In addition to surface area, average pore diameter also increases with increasing activation temperature. Thus, activated carbon with high percentage of porosity and surface area can be developed by controlling the activation temperature during activation process.

Specific surface area

Carbon fibers

10.56431/p-8r6jg7

Cite

Citations (1)

Cyano-functionalized carbazole substituted pyrene derivatives for promising organic light-emitting diodes

Dyes and Pigments (2018)

Vellaichamy Joseph K. R. Justin Thomas Snehasis Sahoo Meenu Singh Jwo‐Huei Jou

Carbazole

Chromophore

Quantum Efficiency

Excimer