Copper (II) Phthalocyanine Based Field Effect Transistors as Total Dose Sensors for Determining Ionizing Radiation Dose

Electronic Devices ◽

Organic Electronic

ABSTRACTChanges in the material properties of copper (II) phthalocyanine (CuPc) thin-films were studied upon exposure to increasing dose of ionizing radiation using photoluminescence spectrum. We observe generation of new energy states below the band gap upon exposure to ionizing radiation. Organic electronic devices – CuPc based resistor and an organic field effect transistor (OFET) – are proposed in this work as total dose sensors for ionizing radiation. We observe an increase in the conductivity of CuPc thin-films with increasing dose of ionizing radiation. To overcome the possibility of changes/degradation in the electrical properties of CuPc thin-films upon interaction with various gases and moisture in the environment, a passivation layer of silicon nitride, deposited by hot-wire CVD process is proposed. Effect of ionizing radiation on the electrical properties of thin-films of CuPc has been studied. We observe a 170% increase in the resistance of the thin-film for a total of 50 Gy radiation dose using Cobalt-60 (60Co) radiation source. Moreover, significant changes in the electrical characteristics of an OFET, with CuPc as an organic semiconductor, have been observed with increasing doses of ionizing radiation. Experiments with an OFET (W/L = 19350 μm / 100 μm and tox = 150 nm) as a sensor resulted in a ∼100X change in the OFF current for a total of 50 Gy dose of ionizing radiation exhibiting a sensitivity of ∼1 nA/Gy. Moreover, implementing a reader circuit, shift in the threshold voltage of the OFET at 1e-7 A drain current displayed a sensitivity of 80 mV/Gy for a total of 50 Gy dose of ionizing radiation. CuPc based organic electronic devices have advantages as sensors because of their low-cost fabrication, large area coverage on flexible substrates, etc.

Purity of organic semiconductors as a key factor for the performance of organic electronic devices

Materials Chemistry Frontiers ◽

10.1039/d0qm00690d ◽

2020 ◽

Vol 4 (12) ◽

pp. 3678-3689

Author(s):

Cigdem Yumusak ◽

Niyazi Serdar Sariciftci ◽

Mihai Irimia-Vladu

Keyword(s):

Organic Semiconductors ◽

Field Effect ◽

High Performance ◽

Electronic Devices ◽

Organic Field Effect Transistors ◽

Organic Electronic ◽

Key Factor ◽

Key Parameter

Effects of purification were studied in organic field effect transistors. The results presented here indicate that the purity of organic semiconductors is a key parameter to achieve high performance for the field of organic field effect transistors.

Ionizing Radiation Total Dose Detectors Using Oligomer Organic Semiconductor Material and Devices

MRS Proceedings ◽

10.1557/opl.2011.902 ◽

2011 ◽

Vol 1312 ◽

Cited By ~ 1

Author(s):

Harshil N. Raval ◽

V. Ramgopal Rao

Keyword(s):

Radiation Dose ◽

Ionizing Radiation ◽

Total Dose ◽

Field Effect ◽

Electrical Measurement ◽

Total Radiation Dose ◽

Γ Rays ◽

Effect Transistor ◽

Electrical Characterizations

ABSTRACTOrganic semiconducting oligomer – Pentacene, as a material and organic electronic devices based on it, are proposed here as total dose detectors for ionizing radiation. Pentacene, when exposed to ionizing radiation of γ – rays using Cobalt – 60 (60Co) radiation source, shows increase in the conductivity of the material which can be used as a sensing phenomenon for determining the dose of ionizing radiation. The change in material property was also verified using UV-visible (UV-VIS) spectrum for pentacene thin-films with rising absorption peaks at the oxidized positions in the wavelength. A pentacene resistor can be used as a detector, as the change in the conductivity of the pentacene film can be easily quantified by measuring the change in resistance of the pentacene resistor after different total radiation dose exposures. The experiments resulted in a sensitivity of 340 kΩ/Gy for a total 100 Gy radiation dose for the pentacene resistor. Furthermore, employing this simple electrical measurement technique for determining the dose of ionizing radiation and to improve the sensitivity of the sensor by transistor action, a pentacene based organic field effect transistor (OFET) was exposed to ionizing radiation. Change in OFF current (IOFF) of the OFET sensor with W/L = 19350 μm/100 μm, suggests a sensitivity of 21 nA/Gy for 100 Gy dose. Also, changes in various other parameters like threshold voltage, subthreshold swing, field effect mobility, number of interface states etc. can be extracted from the electrical characterizations which prove their usefulness as a detector for ionizing radiation.

Convenient fabrication of conjugated polymer semiconductor nanotubes and their application in organic electronics

Royal Society Open Science ◽

10.1098/rsos.180868 ◽

2018 ◽

Vol 5 (8) ◽

pp. 180868

Author(s):

Lanchao Ma ◽

Shuixing Dai ◽

Xiaowei Zhan ◽

Xinyang Liu ◽

Yu Li

Keyword(s):

Organic Solar Cells ◽

Electronic Devices ◽

Solution Concentration ◽

Core Shell ◽

Organic Electronic ◽

Light Emitting ◽

Preparation Conditions ◽

Polymer Semiconductor

Organic heterojunction is indispensable in organic electronic devices, such as organic solar cells, organic light-emitting diodes and so on. Fabrication of core–shell nanostructure provides a feasible and novel way to prepare organic heterojunction, which is beneficial for miniaturization and integration of organic electronic devices. Fabrication of nanotubes which constitute the core–shell structure in large quantity is the key for the realization of application. In this work, a simple and convenient method to prepare nanotubes using conjugated copolymer of perylene diimide and dithienothiophene (P(PDI-DTT)) was demonstrated. The relationship between preparation conditions (solvent atmosphere, solution concentration and pore diameter of templates) and morphology of nanostructure was studied systematically. P(PDI-DTT) nanotubes could be fabricated in regular shape and large quantity by preparing the solution with appropriate concentration and placing anodic aluminium oxide template with nanopore diameter of 200 nm in the solvent atmosphere. The tubular structure was confirmed by scanning electron microscopy. P(PDI-DTT) nanotubes exhibited electron mobility of 0.02 cm 2 V –1 s –1 in field-effect transistors under ambient condition. Light-emitting nanostructures were successfully fabricated by incorporating tetraphenylethylene into polymer nanotubes.

Procedures and Properties for a Direct Nano-Micro Integration of Metal and Semiconductor Nanowires on Si Chips

Journal of Nanotechnology ◽

10.1155/2012/325732 ◽

2012 ◽

Vol 2012 ◽

pp. 1-13 ◽

Cited By ~ 3

Author(s):

Dawit Gedamu ◽

Ingo Paulowicz ◽

Seid Jebril ◽

Yogendra Kumar Mishra ◽

Rainer Adelung

Keyword(s):

Thin Film ◽

Electrical Properties ◽

Field Effect ◽

Electronic Devices ◽

Semiconductor Nanowires ◽

Semiconductor Nanostructures ◽

Wafer Level ◽

Vapor Liquid Solid ◽

Micro Structures

1-dimensional metal and semiconductor nanostructures exhibit interesting physical properties, but their integration into modern electronic devices is often a very challenging task. Finding the appropriate supports for nanostructures and nanoscale contacts are highly desired aspects in this regard. In present work we demonstrate the fabrication of 1D nano- and mesostructures between microstructured contacts formed directly on a silicon chip either by a thin film fracture (TFF) approach or by a modified vapor-liquid-solid (MVLS) approach. In principle, both approaches offer the possibilities to integrate these nano-meso structures in wafer-level fabrications. Electrical properties of these nano-micro structures integrated on Si chips and their preliminary applications in the direction of sensors and field effect transistors are also presented.

AN ORGANIC FIELD EFFECT TRANSISTORS-BASED SENSING PLATFORM FOR ENVIRONMENTAL/SECURITY APPLICATIONS

International Journal of Nanoscience ◽

10.1142/s0219581x11009222 ◽

2011 ◽

Vol 10 (04n05) ◽

pp. 891-898 ◽

Cited By ~ 2

Author(s):

RAVISHANKAR S. DUDHE ◽

HARSHIL N. RAVAL ◽

ANIL KUMAR ◽

V. RAMGOPAL RAO

Keyword(s):

Radiation Dose ◽

Ionizing Radiation ◽

Organic Semiconductor ◽

Field Effect ◽

Semiconductor Layer ◽

Electrical Characteristics ◽

Organic Field Effect Transistors ◽

Γ Radiation ◽

Semiconducting Material

Organic semiconducting material based sensors have been used for various environmental applications. Organic field effect transistors (OFETs) also find their applications in explosive vapor detection and total ionizing radiation dose determination. OFETs using poly 3-hexylthiophene (P3HT), a p-type organic semiconductor material and CuII tetraphenylporphyrin ( CuTPP ) composite as their active material were investigated as sensors for detection of various nitro-based explosive vapors with greater than parts per billion sensitivity range. Significant changes, suitable for sensor response, were observed in ON current (Ion) and transconductance (gm) extracted from electrical characteristics of the OFET after exposure to vapors of various explosive compounds. However, a similar device response was not observed to strong oxidizing agents such as benzoquinone (BQ) and benzophenone (BP). Also, the use of organic semiconducting material sensors for determining total ionizing radiation dose was studied, wherein the conductivity of the material was measured as a function of total ionizing radiation dose. An organic semiconducting material resistor was exposed to γ-radiation and it was observed that the change in resistance was proportional to the ionizing radiation dose. Changes in various parameters extracted from electrical characteristics of the OFET after γ-radiation exposure resulted in an improved sensitivity. To protect the organic semiconductor layer from the degradation in the ambient the sensors were passivated with a thin layer of silicon nitride.

Exploring high temperature templating in non-planar phthalocyanine/copper iodide (111) bilayers

Journal of Materials Chemistry C ◽

10.1039/c4tc02116a ◽

2015 ◽

Vol 3 (2) ◽

pp. 461-465 ◽

Cited By ~ 19

Author(s):

Alexandra J. Ramadan ◽

Luke A. Rochford ◽

Dean S. Keeble ◽

Paul Sullivan ◽

Mary P. Ryan ◽

...

Keyword(s):

Thin Films ◽

High Temperature ◽

Small Molecule ◽

Electronic Devices ◽

Copper Iodide ◽

Organic Electronic ◽

Concurrent Use

Controlling the structure of organic small molecule thin films is of considerable interest for organic electronic devices. Concurrent use of a copper iodide templating layer with deposition onto heated substrates allows previously unreported morphologies and molecular orientations of vanadyl phthalocyanine to be produced.