Ultraviolet photoelectron spectroscopy and inverse photoemission spectroscopy of [6,6]-phenyl-C61-butyric acid methyl ester in gas and solid phases

Akaike, Kouki; Kanai, Kaname; Yoshida, Hiroyuki; Tsutsumi, Jun; Nishi, Toshio; Sato, Naoki; Ouchi, Yukio; Seki, Kazuhiko

doi:10.1063/1.2957588

Cited by 110 publications

(110 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results obtained from [60]PCBM compare favorably with a previous study employing the same techniques. 38 The same trend in increasing electron affinity as observed in DFT and CV results is obtained with IPES measurements. Interestingly, the LUMO level of Ketolactam-1 measured using this method is comparable to the onset electron affinity previously reported as a requirement for air-stable electron transport.…”

Section: Resultssupporting

confidence: 72%

Soluble fullerene derivatives: The effect of electronic structure on transistor performance and air stability

Ball

Bouwer

Kooistra

et al. 2011

Journal of Applied Physics

View full text Add to dashboard Cite

The family of soluble fullerene derivatives comprises a widely studied group of electron transporting molecules for use in organic electronic and optoelectronic devices. For electronic applications, electron transporting (n-channel) materials are required for implementation into organic complementary logic circuit architectures. To date, few soluble candidate materials have been studied that fulfill the stringent requirements of high carrier mobility and air stability. Here we present a study of three soluble fullerenes with varying electron affinity to assess the impact of electronic structure on device performance and air stability. Through theoretical and experimental analysis of the electronic structure, characterization of thin-film structure, and characterization of transistor device properties we find that the air stability of the present series of fullerenes not only depends on the absolute electron affinity of the semiconductor but also on the disorder within the thin-film.

show abstract

Section: Resultssupporting

confidence: 72%

Soluble fullerene derivatives: The effect of electronic structure on transistor performance and air stability

Ball

Bouwer

Kooistra

et al. 2011

Journal of Applied Physics

View full text Add to dashboard Cite

show abstract

“…We obtained ε QP = 7.1 ± 0.1 eV for the hole and ε QP = 3.4 ± 0.1 eV for the electron using I = 600 iterations. These results can be compared to the experimental results E IP = 7.17 eV and E EA = 2.63 eV [59,60]. The agreement for the electron affinity can be improved by replacing the RPA screening with TDDFT screening [61], which gives ε QP = 2.5 ± 0.1 eV for the electron.…”

mentioning

confidence: 99%

Breaking the Theoretical Scaling Limit for Predicting Quasiparticle Energies: The StochasticGWApproach

et al. 2014

View full text Add to dashboard Cite

We develop a formalism to calculate the quasi-particle energy within the GW many-body perturbation correction to the density functional theory (DFT). The occupied and virtual orbitals of the Kohn-Sham (KS) Hamiltonian are replaced by stochastic orbitals used to evaluate the Green function, the polarization potential, and thereby the GW self-energy. The stochastic GW (sGW) relies on novel theoretical concepts such as stochastic time-dependent Hartree propagation, stochastic matrix compression and spatial/temporal stochastic decoupling techniques. Beyond the theoretical interest, the formalism enables linear scaling GW calculations breaking the theoretical scaling limit for GW as well as circumventing the need for energy cutoff approximations. We illustrate the method for silicon nanocrystals of varying sizes with Ne > 3000 electrons.The GW approximation [1, 2] to many-body perturbation theory (MBPT) [3] offers a reliable and accessible theory for quasi-particles (QPs) and their energies [2,[4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], enabling estimation of electronic excitations [19][20][21][22][23][24][25] quantum conductance [26][27][28][29][30] and level alignment in hybrid systems [31,32]. Practical use of GW for large systems is severely limited because of the steep CPU and memory requirements as system size increases. The most computationally intensive element in the GW method, the calculation of the polarization potential (screen Coulomb interaction), involves an algorithmic complexity that scales as the fourth power of the system size [33,34]. Various approaches have been developed to reduce the computational bottlenecks of the GW approach [8,18,23,[33][34][35][36][37]. Despite these advances, GW calculations are still quite expensive for many of the intended applications in the fields of materials science, surface science and nanoscience.In this letter we develop a stochastic, orbital-less, formalism for the GW theory, unique in that it does not reference occupied or virtual orbitals and orbital energies of the KS Hamiltonian. While the approach is inspired by recent developments in electronic structure theory using stochastic orbitals [38][39][40][41][42] it introduces three powerful and basic notions: Stochastic decoupling, stochastic matrix compression and stochastic time-dependent Hartree (sTDH) propagation. The result is a stochastic formulation of GW, where the QP energies become random variables sampled from a distribution with a mean equal to the exact GW energies and a statistical error proportional to the inverse number of stochastic orbitals (iterations, I sGW ).We illustrate the sGW formalism for silicon nanocrystals (NCs) with varying sizes and band gaps [43,44] and demonstrate that the CPU time and memory required by sGW scales nearly linearly with system size, thereby providing means to study QPs excitations in large systems of experimental and technological interest.In the reformulation of the GW approach, we treat the QP energy (ε QP = ω QP ) as a perturbative correction to th...

show abstract

“…A few theoretical works, based on density-functional theory (DFT), have been carried out in the past to look into the electronic structure of the above electron acceptors [59][60][61] leading to a good description of their structural properties. However, the evaluation through DFT of electronic properties such as quasiparticle (QP) energy levels yields results only in qualitative agreement with experiment.…”

Section: Introductionmentioning

confidence: 99%

First-principles investigation of organic photovoltaic materialsC60, C70, [C60]PCBM, and bis-
Qian
¹
,
Umari
²
,
Marzari
³

2015
Phys. Rev. B

View full text Add to dashboard Cite

We present a first-principles investigation of the excited-state properties of electron acceptors in organic photovoltaics including C60, C70, [6,6]-phenyl-C61-butyric-acid-methyl-ester ([C60]PCBM), and bis-[C60]PCBM using many-body perturbation theory within the Hedin's G0W0 approximation and an efficient Lanczos approach. Calculated vertical ionization potentials (VIP) and vertical electron affinities (VEA) of C60 and C70 agree very well with experimental values measured in gas phase. The density of states of all three molecules is also compared to photoemission and inverse photoemission spectra measured on thin-films, exhibiting a close agreement -a rigid energy-gap renormalization owing to intermolecular interactions in the thin-films. In addition, it is shown that the low-lying unoccupied states of [C60]PCBM are all derived from the highest-occupied molecular orbitals and the lowest-unoccupied molecular orbitals of fullerene C60. The functional side group in [C60]PCBM introduces a slight electron transfer to the fullerene cage, resulting in small decreases of both VIP and VEA. This small change of VEA provides a solid justification for the increase of open-circuit voltage when replacing fullerene C60 with [C60]PCBM as the electron acceptor in bulk heterojunction polymer solar cells.

show abstract

Ultraviolet photoelectron spectroscopy and inverse photoemission spectroscopy of [6,6]-phenyl-C61-butyric acid methyl ester in gas and solid phases

Cited by 110 publications

References 18 publications

Soluble fullerene derivatives: The effect of electronic structure on transistor performance and air stability

Soluble fullerene derivatives: The effect of electronic structure on transistor performance and air stability

Breaking the Theoretical Scaling Limit for Predicting Quasiparticle Energies: The StochasticGWApproach

First-principles investigation of organic photovoltaic materialsC60, C70, [C60]PCBM, and bis-
Qian
¹
,
Umari
²
,
Marzari
³

2015
Phys. Rev. B

Contact Info

Product

Resources

About

Ultraviolet photoelectron spectroscopy and inverse photoemission spectroscopy of [6,6]-phenyl-C61-butyric acid methyl ester in gas and solid phases

Cited by 110 publications

References 18 publications

Soluble fullerene derivatives: The effect of electronic structure on transistor performance and air stability

Soluble fullerene derivatives: The effect of electronic structure on transistor performance and air stability

Breaking the Theoretical Scaling Limit for Predicting Quasiparticle Energies: The StochasticGWApproach

First-principles investigation of organic photovoltaic materialsC60, C70, [C60]PCBM, and bis-Qian1, Umari2, Marzari3 2015Phys. Rev. B

Contact Info

Product

Resources

About

First-principles investigation of organic photovoltaic materialsC60, C70, [C60]PCBM, and bis-
Qian
¹
,
Umari
²
,
Marzari
³

2015
Phys. Rev. B