@article{doi:10.1021/acsenergylett.0c02524,

title = {Crystallographic, Optical, and Electronic Properties of the Cs_{2}AgBi_{1}–_{x}In_{x}Br_{6} Double Perovskite: Understanding the Fundamental Photovoltaic Efficiency Challenges},

author = {Laura Schade and Suhas Mahesh and George Volonakis and Marios Zacharias and Bernard Wenger and Felix Schmidt and Sameer Vajjala Kesava and Dharmalingam Prabhakaran and Mojtaba Abdi-Jalebi and Markus Lenz and Feliciano Giustino and Giulia Longo and Paolo G Radaelli and Henry J Snaith},

url = {https://doi.org/10.1021/acsenergylett.0c02524},

doi = {10.1021/acsenergylett.0c02524},

year  = {2021},

date = {2021-02-19},

journal = {ACS Energy Letters},

volume = {6},

number = {3},

pages = {1073-1081},

abstract = {We present a crystallographic and optoelectronic study of the double perovskite Cs2AgBi1–xInxBr6. From structural characterization we determine that the indium cation shrinks the lattice and shifts the cubic-to-tetragonal phase transition point to lower temperatures. The absorption onset is shifted to shorter wavelengths upon increasing the indium content, leading to wider band gaps, which we rationalize through first-principles band structure calculations. Despite the unfavorable band gap shift, we observe an enhancement in the steady-state photoluminescence intensity, and n-i-p photovoltaic devices present short-circuit current greater than that of neat Cs2AgBiBr6 devices. In order to evaluate the prospects of this material as a solar absorber, we combine accurate absorption measurements with thermodynamic modeling and identify the fundamental limitations of this system. Provided radiative efficiency can be increased and the choice of charge extraction layers are specifically improved, this material could prove to be a useful wide band gap solar absorber.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/adma.202003137,

title = {Ruddlesden–Popper-Phase Hybrid Halide Perovskite/Small-Molecule Organic Blend Memory Transistors},

author = {Murali Gedda and Emre Yengel and Hendrik Faber and Fabian Paulus and Joshua A Kreß and Ming-Chun Tang and Siyuan Zhang and Christina A Hacker and Prashant Kumar and Dipti R Naphade and Yana Vaynzof and George Volonakis and Feliciano Giustino and Thomas D Anthopoulos},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202003137},

doi = {https://doi.org/10.1002/adma.202003137},

year  = {2021},

date = {2021-02-01},

journal = {Advanced Materials},

volume = {33},

number = {7},

pages = {2003137},

abstract = {Abstract Controlling the morphology of metal halide perovskite layers during processing is critical for the manufacturing of optoelectronics. Here, a strategy to control the microstructure of solution-processed layered Ruddlesden–Popper-phase perovskite films based on phenethylammonium lead bromide ((PEA)2PbBr4) is reported. The method relies on the addition of the organic semiconductor 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene (C8-BTBT) into the perovskite formulation, where it facilitates the formation of large, near-single-crystalline-quality platelet-like (PEA)2PbBr4 domains overlaid by a ≈5-nm-thin C8-BTBT layer. Transistors with (PEA)2PbBr4/C8-BTBT channels exhibit an unexpectedly large hysteresis window between forward and return bias sweeps. Material and device analysis combined with theoretical calculations suggest that the C8-BTBT-rich phase acts as the hole-transporting channel, while the quantum wells in (PEA)2PbBr4 act as the charge storage element where carriers from the channel are injected, stored, or extracted via tunneling. When tested as a non-volatile memory, the devices exhibit a record memory window (>180 V), a high erase/write channel current ratio (104), good data retention, and high endurance (>104 cycles). The results here highlight a new memory device concept for application in large-area electronics, while the growth technique can potentially be exploited for the development of other optoelectronic devices including solar cells, photodetectors, and light-emitting diodes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acs.nanolett.0c03874,

title = {Theory and Computation of Hall Scattering Factor in Graphene},

author = {Francesco Macheda and Samuel Poncé and Feliciano Giustino and Nicola Bonini},

url = {https://doi.org/10.1021/acs.nanolett.0c03874},

doi = {10.1021/acs.nanolett.0c03874},

year  = {2020},

date = {2020-11-23},

journal = {Nano Letters},

volume = {20},

number = {12},

pages = {8861-8865},

abstract = {The Hall scattering factor, r, is a key quantity for establishing carrier concentration and drift mobility from Hall measurements; in experiments, it is usually assumed to be 1. In this paper, we use a combination of analytical and ab initio modeling to determine r in graphene. Although at high carrier densities r ≈ 1 in a wide temperature range, at low doping the temperature dependence of r is very strong with values as high as 4 below 300 K. These high values are due to the linear bands around the Dirac cone and the carrier scattering rates due to acoustic phonons. At higher temperatures, r can instead become as low as 0.5 due to the contribution of both holes and electrons and the role of optical phonons. Finally, we provide a simple analytical model to compute accurately r in graphene in a wide range of temperatures and carrier densities.},

note = {PMID: 33226824},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Wright2020,

title = {Intrinsic quantum confinement in formamidinium lead triiodide perovskite},

author = {Adam Wright and George Volonakis and Juliane Borchert and Christopher Davies and Feliciano Giustino and Michael B Johnston and Laura M Herz},

url = {https://www.nature.com/articles/s41563-020-0774-9#citeas},

doi = {https://doi.org/10.1038/s41563-020-0774-9},

year  = {2020},

date = {2020-08-24},

journal = {Nature Materials},

volume = {19},

number = {11},

pages = {1201-1206},

abstract = {Understanding the electronic energy landscape in metal halide perovskites is essential for further improvements in their promising performance in thin-film photovoltaics. Here, we uncover the presence of above-bandgap oscillatory features in the absorption spectra of formamidinium lead triiodide thin films. We attribute these discrete features to intrinsically occurring quantum confinement effects, for which the related energies change with temperature according to the inverse square of the intrinsic lattice parameter, and with peak index in a quadratic manner. By determining the threshold film thickness at which the amplitude of the peaks is appreciably decreased, and through ab initio simulations of the absorption features, we estimate the length scale of confinement to be 10–20 nm. Such absorption peaks present a new and intriguing quantum electronic phenomenon in a nominally bulk semiconductor, offering intrinsic nanoscale optoelectronic properties without necessitating cumbersome additional processing steps.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{PhysRevB.102.064412,

title = {Spin waves in metallic iron and nickel measured by soft x-ray resonant inelastic scattering},

author = {N B Brookes and D Betto and K Cao and Yi Lu and K Kummer and F Giustino},

url = {https://link.aps.org/doi/10.1103/PhysRevB.102.064412},

doi = {10.1103/PhysRevB.102.064412},

year  = {2020},

date = {2020-08-14},

journal = {Phys. Rev. B},

volume = {102},

pages = {064412},

publisher = {American Physical Society},

abstract = {The spin-wave dispersions in iron and nickel along the [111] direction are determined using soft x-ray resonant inelastic x-ray scattering (RIXS). For iron, a 10-nm thin film was studied and, over the limited 

q

 range accessible, the peaks disperse as expected for a spin wave and in agreement with inelastic neutron scattering (INS) results. At the higher 

q

 values damping is observed with the peaks weakening and broadening. This damping is less pronounced than in the INS studies. The RIXS results are also compared with ab initio spin fluctuation calculations. The calculations slightly underestimate the energy dispersion and the damping is larger than in the measurement. Nevertheless, the agreement between the RIXS results, INS studies, and the theory is quite satisfactory. For the single crystal of nickel, the measured 

q

 dispersion flattens out rapidly and the peaks broaden. The strong damping effect is reproduced by the spin fluctuation calculations but the energy of the peaks is largely overestimated. Nevertheless, the flattening of the dispersion is not reproduced by the calculations and, although similar effects were observed in early INS experiments, they are not seen in more recent work. Possible reasons for this are discussed. These measurements show that using soft x-ray RIXS to study spin fluctuations in metallic systems, which are in general very challenging for the technique, has much promise. More interestingly, since the iron measurements were performed on a 10-nm thin film, the study opens the possibility to study tailor-made thin-film samples, which cannot be easily studied by other techniques. Combining these studies with state-of-the-art ab initio calculations opens up interesting prospects for testing our understanding of spin waves in metallic systems.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Paudyal2020,

title = {Superconducting properties of MoTe_{2} from ab initio anisotropic Migdal-Eliashberg theory},

author = {H. Paudyal and S. Poncé and F. Giustino and E. R. Margine},

doi = {10.1103/PhysRevB.101.214515},

year  = {2020},

date = {2020-06-01},

journal = {Physical Review B},

volume = {101},

pages = {214515},

publisher = {American Physical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Husanu2020,

title = {Electron-polaron dichotomy of charge carriers in perovskite oxides},

author = {M.-A. Husanu; L. Vistoli; C. Verdi; A. Sander; V. Garcia; J. Rault; F. Bisti; T. Schmitt; F. Giustino; A. S. Mishchenko; M. Bibes; V. N. Strocov},

doi = {10.1038/s42005-020-0330-6},

year  = {2020},

date = {2020-04-03},

journal = {Communications Physics},

volume = {3},

pages = {s42005-020-0330-6},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Zacharias2020,

title = {Theory of the special displacement method for electronic structure calculations at finite temperature},

author = {Marios Zacharias and Feliciano Giustino},

doi = {10.1103/PhysRevResearch.2.013357},

year  = {2020},

date = {2020-03-01},

journal = {Physical Review Research},

volume = {2},

pages = {013357},

publisher = {American Physical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ponce2020,

title = {First-principles calculations of charge carrier mobility and conductivity in bulk semiconductors and two-dimensional materials},

author = {Samuel Poncé and Wenbin Li and Sven Reichardt and Feliciano Giustino},

doi = {10.1088/1361-6633/ab6a43},

year  = {2020},

date = {2020-02-04},

journal = {Reports on Progress in Physics},

volume = {83},

number = {3},

pages = {036501},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Giustino_2020,

title = {The 2021 quantum materials roadmap},

author = {Feliciano Giustino and Jin Hong Lee and Felix Trier and Manuel Bibes and Stephen M Winter and Roser Valent í and Young-Woo Son and Louis Taillefer and Christoph Heil and Adriana I Figueroa and Bernard Pla ç and QuanSheng Wu and Oleg V Yazyev and Erik P A M Bakkers and Jesper Nygård and Pol Forn-D í and Silvano De Franceschi and J W McIver and Foa L E F Torres and Tony Low and Anshuman Kumar and Regina Galceran and Sergio O Valenzuela and Marius V Costache and Aur é and Eun-Ah Kim and Gabriel R Schleder and Adalberto Fazzio and Stephan Roche},

url = {https://doi.org/10.1088/2515-7639/abb74e},

doi = {10.1088/2515-7639/abb74e},

year  = {2020},

date = {2020-01-19},

journal = {Journal of Physics: Materials},

volume = {3},

number = {4},

pages = {042006},

publisher = {IOP Publishing},

abstract = {In recent years, the notion of ‘Quantum Materials’ has emerged as a powerful unifying concept across diverse fields of science and engineering, from condensed-matter and coldatom physics to materials science and quantum computing. Beyond traditional quantum materials such as unconventional superconductors, heavy fermions, and multiferroics, the field has significantly expanded to encompass topological quantum matter, two-dimensional materials and their van der Waals heterostructures, Moiré materials, Floquet time crystals, as well as materials and devices for quantum computation with Majorana fermions. In this Roadmap collection we aim to capture a snapshot of the most recent developments in the field, and to identify outstanding challenges and emerging opportunities. The format of the Roadmap, whereby experts in each discipline share their viewpoint and articulate their vision for quantum materials, reflects the dynamic and multifaceted nature of this research area, and is meant to encourage exchanges and discussions across traditional disciplinary boundaries. It is our hope that this collective vision will contribute to sparking new fascinating questions and activities at the intersection of materials science, condensed matter physics, device engineering, and quantum information, and to shaping a clearer landscape of quantum materials science as a new frontier of interdisciplinary scientific inquiry. We stress that this article is not meant to be a fully comprehensive review but rather an up-to-date snapshot of different areas of research on quantum materials with a minimal number of references focusing on the latest developments.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Schlipf2020,

title = {SternheimerGW: A program for calculating GW quasiparticle band structures and spectral functions without unoccupied states},

author = {Martin Schlipf and Henry Lambert and Nourdine Zibouche and Feliciano Giustino},

doi = {10.1016/j.cpc.2019.07.019},

year  = {2020},

date = {2020-01-01},

journal = {Computer Physics Communications},

volume = {247},

pages = {106856},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Li2020,

title = {Many-body renormalization of the electron effective mass of InSe},

author = {Wenbin Li and Feliciano Giustino},

doi = {10.1103/PhysRevB.101.035201},

year  = {2020},

date = {2020-01-01},

journal = {Physical Review B},

volume = {101},

number = {3},

pages = {035201},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Muratov2019,

title = {Slot-die-printed two-dimensional ZrS_{3} charge transport layer for perovskite light-emitting diodes},

author = {Dmitry S Muratov and Artur R Ishteev and Dmitry A Lypenko and Vladislav O Vanyushin and Pavel Gostishev and Svetlana Perova and Danila S Saranin and Daniele Rossi and Matthias Auf der Maur and George Volonakis and Feliciano Giustino and Per. O Å Persson and Denis V Kuznetsov and Alexander Sinitskii and Di Carlo, Aldo},

doi = {10.1021/acsami.9b16457},

year  = {2019},

date = {2019-12-03},

journal = {ACS Applied Materials & Interfaces},

volume = {11},

number = {51},

pages = {48021-48028},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ponce2019b,

title = {Route to high hole mobility in GaN via reversal of crystal-field splitting},

author = {Samuel Poncé and Debdeep Jena and Feliciano Giustino},

doi = {10.1103/PhysRevLett.123.096602},

year  = {2019},

date = {2019-08-01},

journal = {Physical Review Letters},

volume = {123},

pages = {096602},

publisher = {American Physical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ponce2019c,

title = {Hole mobility of strained GaN from first principles},

author = {Samuel Poncé and Debdeep Jena and Feliciano Giustino},

doi = {10.1103/PhysRevB.100.085204},

year  = {2019},

date = {2019-08-01},

journal = {Physical Review B},

volume = {100},

pages = {085204},

publisher = {American Physical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Sio2019a,

title = {Polarons from first principles, without supercells},

author = {Weng Hong Sio and Carla Verdi and Samuel Poncé and Feliciano Giustino},

doi = {10.1103/PhysRevLett.122.246403},

year  = {2019},

date = {2019-06-01},

journal = {Physical Review Letters},

volume = {122},

pages = {246403},

publisher = {American Physical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Sio2019b,

title = {Ab initio theory of polarons: Formalism and applications},

author = {Weng Hong Sio and Carla Verdi and Samuel Poncé and Feliciano Giustino},

doi = {10.1103/PhysRevB.99.235139},

year  = {2019},

date = {2019-06-01},

journal = {Physical Review B},

volume = {99},

pages = {235139},

publisher = {American Physical Society},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Dette2019b,

title = {Trellises of molecular oxygen on anatase TiO2(101)},

author = {Christian Dette and Miguel A Pérez-Osorio and Shai Mangel and Feliciano Giustino and Soon Jung Jung and Klaus Kern},

doi = {10.1021/acs.jpcc.9b04314},

year  = {2019},

date = {2019-01-01},

journal = {The Journal of Physical Chemistry C},

volume = {123},

number = {43},

pages = {26170-26177},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Lian2019,

title = {Coexistence of superconductivity with enhanced charge density wave order in the two-dimensional limit of TaSe2},

author = {Chao-Sheng Lian and Christoph Heil and Xiaoyu Liu and Chen Si and Feliciano Giustino and Wenhui Duan},

doi = {10.1021/acs.jpclett.9b01480},

year  = {2019},

date = {2019-01-01},

journal = {The Journal of Physical Chemistry Letters},

volume = {10},

number = {14},

pages = {4076-4081},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1021/acs.jpclett.9b00193,

title = {Oxide analogs of halide perovskites and the new semiconductor Ba2AgIO6},

author = {George Volonakis and Nobuya Sakai and Henry J Snaith and Feliciano Giustino},

doi = {10.1021/acs.jpclett.9b00193},

year  = {2019},

date = {2019-01-01},

journal = {The Journal of Physical Chemistry Letters},

volume = {10},

number = {8},

pages = {1722-1728},

keywords = {},

pubstate = {published},

tppubtype = {article}

}