Approaching the Trap-Free Limit in Organic Single-Crystal Field-Effect Transistors

Blülle, Balthasar; Häusermann, Roger; Batlogg, B.

doi:10.1103/physrevapplied.1.034006

Cited by 85 publications

(56 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Judging from the comparison between C 8 -DNBDT-NW OFETs situated with (i) and (ii), trap DOS is apparently influenced by the quality of semiconductor/ dielectric interface; random potential, which may be induced by imperfection of surface treatment of dielectric interface, can be a major impediment not only for solution crystallization, but also for charge transport. Given the fact that the trap DOS for rubrene single crystals grown by physical vapor transport is measured to be significantly lower 41 , residual solvent may induce additional traps in our solution-processed crystalline films. However, in recent synchrotron X-ray diffraction measurements, we do not see any trapped solvent molecules in the bulk crystal structure of C 8 -DNBDT-NW 8 .…”

Section: Resultsmentioning

confidence: 99%

“…Black lines represent those computed from transfer characteristics (see Supplementary Note 6). The error bars represent compound errors that result from propagation of the uncertainties in S I D =I 2 D and transconductance the transport level as follows 41 ; Given the Debye length λ D ¼ ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ϵk B T=ne 2 p À Á , where ϵ is the permittivity of the organic semiconductor, the drain current (I D ) can be written as:…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Remarkably low flicker noise in solution-processed organic single crystal transistors

et al. 2018

Self Cite

View full text Add to dashboard Cite

Low-frequency noise generated by a fluctuation of current is a key issue for integrating electronic elements into a high-density circuit. Investigation of the noise in organic field-effect transistors is now sharing the spotlight with development of printed integrated circuits. The recent improvement of field-effect mobility (up to 15 cm 2 V −1 s −1 ) has allowed for organic integrated circuits with a relatively high-speed operation (~50 kHz). Therefore, an in-depth understanding of the noise feature will be indispensable to further improve the circuit stability and durability. Here we performed noise measurements in solution-processed organic single crystal transistors, and discovered that a low trap density-of-states due to the absence of structural disorder in combination with coherent band-like transport gives rise to an unprecedentedly low flicker noise. The excellent noise property in organic single crystals will allow their potential to be fully exploited for high-speed communication and sensing applications.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Remarkably low flicker noise in solution-processed organic single crystal transistors

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…Moreover, rubrene shows high singlet fission efficiencies in both, single crystals 22,23 and amorphous thin films 24 . Rubrene became thus a model system to study intermolecular interactions and charge transport properties of molecular solid states 10,20,21,[25][26][27][28][29][30][31] . The outstanding charge transport properties might be related to the peculiar molecular structure of rubrene with the frontier orbitals mainly located on the tetracene backbone and the electronically inactive phenyl side groups 28,[32][33][34] .…”

Section: Introductionmentioning

confidence: 99%

Transient Monolayer Structure of Rubrene on Graphite: Impact on Hole–Phonon Coupling

Bussolotti

Xin

et al. 2016

J. Phys. Chem. C

View full text Add to dashboard Cite

Charge transport in molecular thin films is often dominated by incoherent hopping processes and charge-carrier phonon coupling plays a major role in defining mobilities. Our high resolution angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) study reveals the influence of molecular configuration and packing on the hole-phonon coupling in vacuum-sublimed thin films of rubrene on graphite and allows determining charge reorganization energies. In the contact layer to the substrate rubrene is well-ordered with, for low coverages, the tetracene backbone being almost parallel to the graphite surface forming a loose-packed monolayer. Increasing the coverage leads to an orientational transition and a more tilted orientation of rubrene in a close-packed monolayer. This transition results in dramatic changes of spectral features in ARUPS including the photoelectron angular distribution of the highest occupied molecular orbital derived intensity. The charge reorganization energy, however, only changes slightly. The transient monolayer structure of rubrene on graphite allows thus to demonstrate that hole-phonon coupling in organic thin films does not depend very critically on the packing structure. IntroductionLow charge-carrier mobilities are often limiting the performance of organic (opto-)electronic devices as charge transport in organic semiconductor thin films is often dominated by incoherent hopping processes 1-4 . Hopping mobilities depend critically on the charge-carrier phonon coupling 5-8 , which determines the charge reorganization energy λ. In most molecular thin films intermolecular interactions are weak and λ is consequently dominated by intramolecular vibrations and is often taken from gas-phase calculations 5,9-11 or gas-phase ultraviolet photoelectron spectroscopy (UPS) data 9,12-14 . However, the relevant quantities for device application are the solid state values, which depend on the molecular surrounding, i.e. the interaction with neighboring molecules and/or a substrate 7,15 . Due to the similarities of ionization (followed by neutralization) during localized hopping transport and photoionization, UPS is the method of choice to measure charge reorganization energies of organic thin films by an analysis of the vibrational fine structure of the highest occupied molecular orbital (HOMO)-derived peak 7,8,[15][16][17][18] . The relevant vibrational energies (hν i ) of a molecule are often centered closely and in good approximation the analysis can be done by a single mode fit with one main vibrational energy (hν) 19 . Moreover, in most molecular thin films the relaxation energies for ionization and neutralization of a molecule are rather similar and the charge reorganization energy is thus simply given by λ=2Shν with S being the Huang-Rhys factor, which is determined by the relative intensity contribution to the vibrational progressions 7,13 .

show abstract

“…For practical applications, a subthreshold swing (S), which is the inverse of the logarithmic slope of the drain current (I D ) versus gate voltage (V G ) in the subthreshold regime, is an important characteristic in addition to the mobility. 28 In fact, the devices with smaller S can be operated by lower V G . Given the assumption that the trap density in the bulk is zero, the trap density at the interface per unit area (D it ) can be estimated as follows:…”

mentioning

confidence: 99%

“…Note that S is related to the deep trap at the interface. 28 Table II summarizes the averaged S and D it of three devices: for the device only with SAM, for the one with PMMA and SAM, and for the one only with PMMA (Transistor characteristics of typical devices are shown in Figure S1 in the supplementary material). Here again, the value of 34.5 nF cm À2 was used as C i in all types of devices.…”

mentioning

confidence: 99%

Spontaneously formed high-performance charge-transport layers of organic single-crystal semiconductors on precisely synthesized insulating polymers

Makita

Sasaki

Annaka

et al. 2017

Applied Physics Letters

View full text Add to dashboard Cite

Charge-transporting semiconductor layers with high carrier mobility and low trap-density, desired for high-performance organic transistors, are spontaneously formed as a result of thermodynamic phase separation from a blend of π-conjugated small molecules and precisely synthesized insulating polymers dissolved in an aromatic solvent. A crystal film grows continuously to the size of centimeters, with the critical conditions of temperature, concentrations, and atmosphere. It turns out that the molecular weight of the insulating polymers plays an essential role in stable film growth and interfacial homogeneity at the phase separation boundary. Fabricating the transistor devices directly at the semiconductor-insulator boundaries, we demonstrate that the mixture of 3,11-didecyldinaphtho[2,3-d:2′,3′-d′]benzo[1,2-b:4,5-b′]dithiophene and poly(methyl methacrylate) with the optimized weight-average molecular weight shows excellent device performances. The spontaneous phase separation with a one-step fabrication process leads to a high mobility up to 10 cm2 V−1 s−1 and a low subthreshold swing of 0.25 V dec−1 even without any surface treatment such as self-assembled monolayer modifications on oxide gate insulators.

show abstract

Approaching the Trap-Free Limit in Organic Single-Crystal Field-Effect Transistors

Cited by 85 publications

References 39 publications

Remarkably low flicker noise in solution-processed organic single crystal transistors

Remarkably low flicker noise in solution-processed organic single crystal transistors

Transient Monolayer Structure of Rubrene on Graphite: Impact on Hole–Phonon Coupling

Spontaneously formed high-performance charge-transport layers of organic single-crystal semiconductors on precisely synthesized insulating polymers

Contact Info

Product

Resources

About