Query: Polymer and organic nonvolatile memory devices

Candidate papers:

abstract: Organic molecules and semiconductors have been proposed as active part of a large variety of nonvolatile memory devices, including resistors, diodes and transistors. In this review, we focus on electrically reprogrammable nonvolatile memories. We classify several possible devices according to their operation principle and critically review the role of the p conjugated materials in the device operation. We propose specifications for applications for organic nonvolatile memory and review the state of the art with respect to these target specifications. Conclusions are drawn regarding further work on materials and device architectures.
author_names: Paul Heremans

Gerwin H Gelinck

Robert Muller

Kang-Jun Baeg

Dong-Yu Kim

Yong-Young Noh
title: Polymer and Organic Nonvolatile Memory Devices
year: 2011

abstract: Abstract Charge trapping is an undesirable phenomenon and a common challenge in the operation of n channel organic field effect transistors. Herein, we exploit charge trapping in an n type semiconducting poly (naphthalene diimide alt biselenophene) (PNDIBS) as the key operational mechanism to develop high performance, nonvolatile, electronic memory devices. The PNDIBS based field effect transistor memory devices were programmed at 60 V and they showed excellent charge trapping and de trapping characteristics, which could be cycled more than 200 times with a current ratio of 103 between the two binary states. Programmed data could be retained for 103 s with a memory window of 28 V. This is a record performance for n channel organic transistor with inherent charge trapping capability without using external charge trapping agents. However, the memory device performance was greatly reduced, as expected, when the n type polymer semiconductor was end capped with phenyl groups to reduce the trap density. These results show that the trap density of n type semiconducting polymers could be engineered to control the inherent charge trapping capability and device performance for developing high performance low cost memory devices.
author_names: Nishit M Murari

Ye-Jin Hwang

Felix Sunjoo Kim

Samson A Jenekhe
title: Organic nonvolatile memory devices utilizing intrinsic charge trapping phenomena in an n type polymer semiconductor
year: 2016

abstract: A molecular nano floating gate (NFG) of pentacene based transistor memory devices is developed using conjugated polymer nanoparticles (CPN) as the discrete trapping sites embedded in an insulating polymer, poly (methacrylic acid) (PMAA) The nanoparticles of polyfluorene (PF) and poly(fluorene alt benzo[2,1,3]thiadiazole (PFBT) with average diameters of around 50 70 nm are used as charge trapping sites, while hydrophilic PMAA serves as a matrix and a tunneling layer. By inserting PF nanoparticles as the floating gate, the transistor memory device reveals a controllable threshold voltage shift, indicating effectively electron trapping by the PF CPN. The electron storage capability can be further improved using the PFBT based NFG since their lower unoccupied molecular orbital level is beneficial for stabilization of the trapped charges, leading a large memory window (35 V) retention time longer than 104 s with a high ON/OFF ratio of >104. In addition, the memory device performance using conjugated polymer nanoparticle NFG is much higher than that of the corresponding polymer blend thin films of PF/polystyrene. It suggests that the discrete polymer nanoparticles can be effectively covered by the tunneling layer, PMAA, to achieve the superior memory characteristics.
author_names: Chien-Chung Shih

Yu-Cheng Chiu

Wen-Ya Lee

Jung-Yao Chen

Wen-Chang Chen
title: Conjugated Polymer Nanoparticles as Nano Floating Gate Electrets for High Performance Nonvolatile Organic Transistor Memory Devices
year: 2015

abstract: By means of the limited conjugation length, the intrinsic 3 dimensional conformations and the potential nanoporous structures, p conjugation interrupted hyperbranched polymers (CIHPs) were demonstrated as polymer electrets for the application of organic transistor memory devices. As models of CIHPs, PPF and PPF8 were synthesized via Friedel Crafts C H polymerization for investigation of the structure performance relationship according to four element theory. They exhibited good solubility in organic solvents, excellent thermal stability and film forming ability. The preliminary as fabricated transistors showed memory effects with large hysteresis windows and reliable programming/erasing cycles. Furthermore, devices based on PPF exhibited higher mobility, larger ON/OFF ratio and better data retention capability than those based on PPF8. The negative effect of the substitution of alkoxyl groups on the device performance suggests that charge trapping and storage are highly sensitive with electrets' molecular orbital energy levels, vibration relaxation mode, chain aggregates, and surface energy. Soluble organic framework polymers will be potential advanced organic nanomaterials for plastic electronics and mechatronics.
author_names: Jin-yi Lin

Wen Zhi Li

Zhen Yu

Ming-dong Yi

Haifeng Ling

Linghai Xie

Sheng-biao Li

Wei Huang
title: p Conjugation interrupted hyperbranched polymer electrets for organic nonvolatile transistor memory devices
year: 2014

abstract: We report the synthesis of poly(5 hexyl 2 vinylthiophene) (PVT) and poly(5 hexyl 5' vinyl 2,2':5,2' terthiophene) (PVTT) as charge storage electrets for nonvolatile organic field effect transistor (OFET) memory devices of n type semiconducting N,N' bis(2 phenylethyl)perylene 3,4,9,10 bis(dicarboximide) (BPE PTCDI) The effects of the conjugated thiophene chain length on the morphology, OFET mobility and memory characteristics are explored and compared to those of the styrene or fluorene side chain. The mobility of the OFET memory device using PVTT as an electret is significantly smaller compared with that of PVT because its large torsional angle hinders the molecular packing of BPE PTCDI. However, the OFET memory device using the PVTT electret has the largest hysteresis window of 81 V, compared to PVT, polystyrene (PS) and poly(styrene) para substituted with fluorene (PSt Fl) The highest HOMO energy level of PVTT facilitates the charge transfer from BPE PTCDI and leads to the largest memory window. The backbone non coplanarity prevents the back transfer of the charge for the nonvolatile memory characteristics. The device shows excellent nonvolatile behavior for bistable switching and the write read erase read (WRER) cycles are operated over 100 cycles. The shifted threshold voltages of the OFET memory devices using PVTT are stable over 104 s, and the ON and OFF states could maintain 104 s with the Ion/Ioff current ratios of 103. This study suggests that the pendent conjugation length and the backbone coplanarity of polymer electrets significantly affect the charge mobility and electrical characteristics of OFET memory devices.
author_names: Ying-Hsuan Chou

Sanae Takasugi

Raita Goseki

Takashi Ishizone

Wen-Chang Chen
title: Nonvolatile organic field effect transistor memory devices using polymer electrets with different thiophene chain lengths
year: 2014

abstract: Polymer ferroelectric laser induced periodic surface structures (LIPSS) have been prepared on ferroelectric thin films of a poly(vinylidene fluoride trifluoroethylene) copolymer. Although this copolymer does not absorb light at the laser wavelength, LIPSS on the copolymer can be obtained by forming a bilayer with other light absorbing polymers. The ferroelectric nature of the structured bilayer was proven by piezoresponse force microscopy measurements. Ferroelectric hysteresis was found on both the bilayer and the laser structured bilayer. We show that it is possible to write ferroelectric information at the nanoscale. The laser structured ferroelectric bilayer showed an increase in the information storage density of an order of magnitude, in comparison to the original bilayer.
author_names: Daniel E Martinez-Tong

Alvaro Rodriguez-Rodriguez

Aurora Nogales

Mari Cruz Garcia-Gutierrez

Francesc Perez-Murano

Jordi Llobet

Tiberio A Ezquerra

Esther Rebollar
title: Laser Fabrication of Polymer Ferroelectric Nanostructures for Nonvolatile Organic Memory Devices.
venue: ACS applied materials interfaces
year: 2015

author_names: Fumiya Shiono

Takashi Nagase

Takashi Kobayashi

Hiroyoshi Naito
title: Solution processed Top gate Nonvolatile Organic Transistor Memory Devices with Soluble Fullerene polymer Composite as Charge Storage Layers
year: 2016

author_names: Chien-Chung Shih

Yu-Cheng Chiu

Wen-Ya Lee

Jung-Yao Chen

Wen-Chang Chen
title: Organic Electronics: Conjugated Polymer Nanoparticles as Nano Floating Gate Electrets for High Performance Nonvolatile Organic Transistor Memory Devices (Adv. Funct. Mater. 10/2015)
year: 2015

abstract: Nonvolatile memory devices based on the pentacene film and controlled gold nanoparticle (Au np /polymer composite layers were developed. Organic field effect transistor based nonvolatile memory devices having self assembled Au np exhibited controllable and reliable current level differences (on and off states) according to the applied gate voltages (programming/erasing operations) The memory devices showed large memory windows as well as good data retention properties by adopting charge storage layers of controlled Au np separated by insulating polymer layers. The process for fabricating nonvolatile memory devices was based on the solution processes and organic semiconductor layers, so it has a potential use in flexible nonvolatile memory applications.
author_names: Yong-mu Kim

Young-Su Park

and Josephine P O'Reilly

Jang-Sik Lee
title: Organic Field Effect Transistor Based Nonvolatile Memory Devices Having Controlled Metallic Nanoparticle/Polymer Composite Layers
year: 2010

abstract: We present data, which were obtained before bending and after bending, for the electrical bistabilities, memory stabilities, and memory mechanisms of three layer structured flexible bistable organic memory (BOM) devices, which were fabricated utilizing the ultrathin graphite sheets (UGS) sandwiched between insulating poly(methylmethacrylate) (PMMA) polymer layers. The UGS were formed by transferring UGS (about 30 layers) and using a simple spin coating technique. Transmission electron microscopy (TEM) measurements were performed to investigate the microstructural properties of the PMMA/UGS/PMMA films. Current voltage (I V) measurements were carried out to investigate the electrical properties of the BOM devices containing the UGS embedded in the PMMA polymer. Current time (I t) and current cycle measurements under flat and bent conditions were performed to investigate the memory stabilities of the BOM devices. The memory characteristics of the BOM maintained similar device efficiencies after bending and were stable during repeated bendings of the BOM devices. The mechanisms for these characteristics of the fabricated BOM are described on the basis of the I V results.
author_names: Dong Ick Son

Jae Ho Shim

Dong Hee Park

Jae Hun Jung

Jung Min Lee

Won Il Park

Tae Whan Kim

Won Kook Choi
title: Polymer ultrathin graphite sheet polymer composite structured flexible nonvolatile bistable organic memory devices.
venue: Nanotechnology
year: 2011