Defect states and their energetic position and distribution in organic molecular semiconductors

2013 ◽  
Vol 102 (14) ◽  
pp. 143301 ◽  
Author(s):  
Akanksha Sharma ◽  
Sarita Yadav ◽  
Pramod Kumar ◽  
Sumita Ray Chaudhuri ◽  
Subhasis Ghosh
Keyword(s):  
Defect States ◽  
Molecular Semiconductors ◽  
Energetic Position

Photoactive donor-acceptor thin films as prospective materials for evaporated bulk heterojunctions of molecular semiconductors

2008 ◽  
Author(s):  
Derck Schlettwein ◽  
Robin Knecht ◽  
Dominik Klaus ◽  
Christopher Keil ◽  
Günter Schnurpfeil
Keyword(s):  
Thin Films ◽  
Bulk Heterojunctions ◽  
Donor Acceptor ◽  
Molecular Semiconductors

Spectrum of Defect States in Porous Organic Low-k Dielectric Films, Annealed in Argon and Nitrogen

2003 ◽  
Vol 766 ◽  
Author(s):  
V. Ligatchev ◽  
T.K.S. Wong ◽  
T.K. Goh ◽  
Rusli Suzhu Yu
Keyword(s):  
Deep Level ◽  
Dielectric Films ◽  
Silicon Substrates ◽  
Reverse Bias Voltage ◽  
Defect States ◽  
Single Side ◽  
Sandwich Type ◽  
Transient Spectroscopy ◽  
P Type ◽  
Spectrum Deconvolution

AbstractDefect spectrum N(E) of porous organic dielectric (POD) films is studied with capacitance deep-level-transient-spectroscopy (C-DLTS) in the energy range up to 0.7 eV below conduction band bottom Ec. The POD films were prepared by spin coating onto 200mm p-type (1 – 10 Δcm) single-side polished silicon substrates followed by baking at 325°C on a hot plate and curing at 425°C in furnace. The film thickness is in the 5000 – 6000 Å range. The ‘sandwich’ -type NiCr/POD/p-Si/NiCr test structures showed both rectifying DC current-voltage characteristics and linear 1/C2 vs. DC reverse bias voltage. These confirm the applicability of the C-DLTS technique for defect spectrum deconvolution and the n-type conductivity of the studied films. Isochronal annealing (30 min in argon or 60 min in nitrogen) has been performed over the temperature range 300°C - 650°C. The N(E) distribution is only slightly affected by annealing in argon. However, the distribution depends strongly on the annealing temperature in nitrogen ambient. A strong N(E) peak at Ec – E = 0.55 – 0.60 eV is detected in all samples annealed in argon but this peak is practically absent in samples annealed in nitrogen at Ta < 480°C. On the other hand, two new peaks at Ec – E = 0.12 and 0.20 eV appear in the N(E) spectrum of the samples annealed in nitrogen at Ta = 650°C. The different features of the defect spectrum are attributed to different interactions of argon and nitrogen with dangling carbon bonds on the intra-pore surfaces.

EPR spectra and defect states in glasses of the GexS100-x system

1982 ◽  
Vol 47 (7) ◽  
pp. 1787-1793 ◽  
Author(s):  
Miloslav Frumar ◽  
Gustáv Plesch ◽  
Eva Černošková ◽  
Václav Černý ◽  
Ladislav Tichý ◽  
...  
Keyword(s):  
Experimental Data ◽  
Epr Spectra ◽  
Defect States ◽  
Composition Region ◽  
Active Defect ◽  
Temperature Conditions ◽  
Defect Centres

Glasses of the GexS100-x system were studied in the region of 30 ⪬ x ⪬ 45. The concept of magnetically active defect centres was employed to account for the EPR spectra of pure samples as well as those doped with silver or iodine, prepared in different temperature conditions. In terms of this concept a consistent interpretation of the experimental data could be given for the composition region applied.

The Instability Characteristics of Amorphous Silicon Thin Film Transistors with Various Interfacial and Bulk Defect States

1997 ◽  
Vol 36 (Part 1, No. 10) ◽  
pp. 6226-6229 ◽  
Author(s):  
Huang-Chung Cheng ◽  
Jun-Wei Tsai ◽  
Chun-Yao Huang ◽  
Fang-Chen Luo ◽  
Hsing-Chien Tuan
Keyword(s):  
Thin Film ◽  
Amorphous Silicon ◽  
Thin Film Transistors ◽  
Defect States ◽  
Silicon Thin Film

scholarly journals Correlation between Defects and Electrical Performances of Ion-Irradiated 4H-SiC p–n Junctions

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1966
Author(s):  
Domenico Pellegrino ◽  
Lucia Calcagno ◽  
Massimo Zimbone ◽  
Salvatore Di Franco ◽  
Antonella Sciuto
Keyword(s):  
Deep Level ◽  
Electrical Characterization ◽  
High Fluence ◽  
Defect States ◽  
Exponential Parameter ◽  
Current Voltage ◽  
Different Temperatures ◽  
In Series ◽  
Transient Spectroscopy ◽  
Fluence Range

In this study, 4H-SiC p–n junctions were irradiated with 700 keV He+ ions in the fluence range 1.0 × 1012 to 1.0 × 1015 ions/cm2. The effects of irradiation were investigated by current–voltage (I–V) and capacitance–voltage (C–V) measurements, while deep-level transient spectroscopy (DLTS) was used to study the traps introduced by irradiation defects. Modifications of the device’s electrical performances were observed after irradiation, and two fluence regimes were identified. In the low fluence range (≤1013 ions/cm2), I–V characteristics evidenced an increase in series resistance, which can be associated with the decrease in the dopant concentration, as also denoted by C–V measurements. In addition, the pre-exponential parameter of junction generation current increased with fluence due to the increase in point defect concentration. The main produced defect states were the Z1/2, RD1/2, and EH6/7 centers, whose concentrations increased with fluence. At high fluence (>1013 ions/cm2), I–V curves showed a strong decrease in the generation current, while DLTS evidenced a rearrangement of defects. The detailed electrical characterization of the p–n junction performed at different temperatures highlights the existence of conduction paths with peculiar electrical properties introduced by high fluence irradiation. The results suggest the formation of localized highly resistive regions (realized by agglomeration of point defects) in parallel with the main junction.

Novel thermally activated delayed fluorescence materials by high-throughput virtual screening: going beyond donor–acceptor design

2021 ◽  
Vol 9 (9) ◽  
pp. 3324-3333 ◽  
Author(s):  
Ke Zhao ◽  
Ömer H. Omar ◽  
Tahereh Nematiaram ◽  
Daniele Padula ◽  
Alessandro Troisi
Keyword(s):  
Virtual Screening ◽  
Quantum Chemistry ◽  
High Throughput ◽  
Delayed Fluorescence ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Quantum Chemistry Calculations ◽  
Donor Acceptor ◽  
Molecular Semiconductors ◽  
High Throughput Virtual Screening

125 potential TADF candidates are identified through quantum chemistry calculations of 700 molecules derived from a database of 40 000 molecular semiconductors. Most of them are new and some do not belong to the class of donor–acceptor molecules.

Quantum Light Emission from Coupled Defect States in DNA-Functionalized Carbon Nanotubes

ACS Nano ◽  
2021 ◽  
Author(s):  
Yu Zheng ◽  
Younghee Kim ◽  
Andrew C. Jones ◽  
Gabrielle Olinger ◽  
Eric R. Bittner ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Light Emission ◽  
Defect States ◽  
Functionalized Carbon Nanotubes
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