Pyrene–oxadiazoles for organic light-emitting diodes: triplet to singlet energy transfer and role of hole-injection/hole-blocking materials

S Chidirala, H Ulla, A Valaboju, MR Kiran… - The Journal of …, 2016 - ACS Publications
Three pyrene–oxadiazole derivatives were synthesized and characterized by optical,
electrochemical, thermal, and theoretical investigations to obtain efficient multifunctional …

Synthesis, photophysical and electroluminescence studies of new triphenylamine-phenanthroimidazole based materials for organic light emitting diodes

J Tagare, H Ulla, MN Satyanarayan… - Journal of …, 2018 - Elsevier
In this work, two star-shaped small conjugated materials, namely tris (4-(1-phenyl-1H-
phenanthro [9, 10-d] imidazol-2-yl) phenyl) amine (PIPTPA) and tris (4-(1-p-tolyl-1H …

New green emitters based on push-pull type pyrene substituted cyanopyridones: Design strategies and utilization in organic light-emitting diodes

KS Vishrutha, H Ulla, BR Bhat, AV Adhikari - Dyes and Pigments, 2023 - Elsevier
A novel series of DAD type conjugated dyes (Py-CyP1-7) centred on a strongly electron-
withdrawing cyanopyridone scaffold (A) linked to highly electron-donating pyrene unit (D) …

Effect of hole-transport layer thickness on the performance of organic light-emitting diodes

H Ulla, MR Kiran, SN Ansari, WA Mir, WM Girma… - Optical Materials, 2024 - Elsevier
In this study, we investigated the influence of hole-transport layer thickness (0, 5, 10, 15, 20,
25, 30, 35 and 40 nm), N, N′-bis (naphthalen-1-yl)-N, N′-bis (phenyl)-2, 2 …

Blue emitting 1, 8-naphthalimides with electron transport properties for organic light emitting diode applications

H Ulla, MR Kiran, B Garudachari, TN Ahipa… - Journal of Molecular …, 2017 - Elsevier
In this article, the synthesis, characterization and use of two novel naphthalimides as
electron-transporting emitter materials for organic light emitting diode (OLED) applications …

Effect of deposition rate on the charge transport in Vanadyl-phthalocyanine thin films

MR Kiran, H Ulla, MN Satyanarayan, G Umesh - Synthetic Metals, 2017 - Elsevier
We report fabrication of Vanadyl phthalocyanine (VOPc) based diodes with different
deposition rates (0.1, 1 and 5 Å/s) in hole only device configuration: ITO/MoO 3/VOPc/MoO …

Star‐Shaped Phenanthroimidazole‐Triphenylamine‐Based Yellow Organic Emitter for Organic Light Emitting Diodes

J Tagare, H Ulla, AB Kajjam, MN Satyanarayan… - …, 2017 - Wiley Online Library
In this work, new star‐shaped conjugated organic emitter, namely tris (4‐(1‐(9, 9‐diethyl‐9H‐
fluoren‐2‐yl)‐1H‐phenanthro [9, 10‐d] imidazol‐2‐yl) phenyl) amine (PIFTPA) with donor‐π …

Investigation of hole transport in α-NPD using impedance spectroscopy with F4TCNQ as hole-injection layer

JM Fernandes, MR Kiran, H Ulla… - Superlattices and …, 2015 - Elsevier
The charge carrier transport is studied in N, N′-di (1-naphthyl)-N, N′-diphenyl-(1, 1′-
biphenyl)-4, 4′-diamine (α-NPD) with the incorporation of sequentially doped p-type …

Optoelectronic properties of novel alkyl-substituted Triphenylamine derivatives

JM Fernandes, C Swetha, E Appalnaidu, K Navamani… - Organic …, 2017 - Elsevier
Hole transport characteristics in three new organic compounds based on triphenylamine
(TPA) moiety are presented. The effect on electrical and optical properties of TPA, attached …

Investigation of charge transport in Vanadyl-phthalocyanine with molybdenum trioxide as a buffer layer: Impedance spectroscopic analysis

MR Kiran, H Ulla, MN Satyanarayan, G Umesh - Synthetic Metals, 2015 - Elsevier
Charge transport in organic materials is one of the intrinsic properties, which governs the
device performance. In this paper, we report the fabrication and electrical characterization of …