Tara Peña

All Publications

• Patternable Process-Induced Strain in 2D Monolayers and Heterobilayers. ACS nano Zhang, Y., Hossain, M. A., Hwang, K. J., Ferrari, P. F., Maduzia, J., Peña, T., Wu, S. M., Ertekin, E., van der Zande, A. M. 2024

  Abstract

  Strain engineering in two-dimensional (2D) materials is a powerful but difficult to control approach to tailor material properties. Across applications, there is a need for device-compatible techniques to design strain within 2D materials. This work explores how process-induced strain engineering, commonly used by the semiconductor industry to enhance transistor performance, can be used to pattern complex strain profiles in monolayer MoS2 and 2D heterostructures. A traction-separation model is identified to predict strain profiles and extract the interfacial traction coefficient of 1.3 ± 0.7 MPa/μm and the damage initiation threshold of 16 ± 5 nm. This work demonstrates the utility to (1) spatially pattern the optical band gap with a tuning rate of 91 ± 1 meV/% strain and (2) induce interlayer heterostrain in MoS2-WSe2 heterobilayers. These results provide a CMOS-compatible approach to design complex strain patterns in 2D materials with important applications in 2D heterogeneous integration into CMOS technologies, moiré engineering, and confining quantum systems.

  View details for DOI 10.1021/acsnano.3c09354

  View details for PubMedID 38266246

• Strain engineering in 2D hBN and graphene with evaporated thin film stressors APPLIED PHYSICS LETTERS Azizimanesh, A., Dey, A., Chowdhury, S. A., Wenner, E., Hou, W., Pena, T., Askari, H., Wu, S. M. 2023; 123 (4)

  View details for DOI 10.1063/5.0153935

  View details for Web of Science ID 001037218600010

• Moire engineering in 2D heterostructures with process-induced strain APPLIED PHYSICS LETTERS Pena, T., Dey, A., Chowdhury, S. A., Azizimanesh, A., Hou, W., Sewaket, A., Watson, C., Askari, H., Wu, S. M. 2023; 122 (14)

  View details for DOI 10.1063/5.0142406

  View details for Web of Science ID 000964331000002

• An Atomistic Insight into Moire Reconstruction in Twisted Bilayer Graphene beyond the Magic Angle. ACS applied engineering materials Dey, A., Chowdhury, S. A., Pena, T., Singh, S., Wu, S. M., Askari, H. 2023; 1 (3): 970-982

  Abstract

  Twisted bilayer graphene exhibits electronic properties strongly correlated with the size and arrangement of moire patterns. While rigid rotation of the two graphene layers results in a moire interference pattern, local rearrangements of atoms due to interlayer van der Waals interactions result in atomic reconstruction within the moire cells. Manipulating these patterns by controlling the twist angle and externally applied strain provides a promising route to tuning their properties. Atomic reconstruction has been extensively studied for angles close to or smaller than the magic angle (theta m = 1.1°). However, this effect has not been explored for applied strain and is believed to be negligible for high twist angles. Using interpretive and fundamental physical measurements, we use theoretical and numerical analyses to resolve atomic reconstruction in angles above theta m . In addition, we propose a method to identify local regions within moire cells and track their evolution with strain for a range of representative high twist angles. Our results show that atomic reconstruction is actively present beyond the magic angle, and its contribution to the moire cell evolution is significant. Our theoretical method to correlate local and global phonon behavior further validates the role of reconstruction at higher angles. Our findings provide a better understanding of moire reconstruction in large twist angles and the evolution of moire cells under the application of strain, which might be potentially crucial for twistronics-based applications.

  View details for DOI 10.1021/acsaenm.2c00259

  View details for PubMedID 37008886

• Ultrasonic delamination based adhesion testing for high-throughput assembly of van der Waals heterostructures JOURNAL OF APPLIED PHYSICS Pena, T., Holt, J., Sewaket, A., Wu, S. M. 2022; 132 (22)

  View details for DOI 10.1063/5.0126446

  View details for Web of Science ID 000895982900006

• Dynamic adhesion of 2D materials to mixed-phase BiFeO3 structural phase transitions JOURNAL OF APPLIED PHYSICS Watson, C., Pena, T., Abdin, M., Khan, T., Wu, S. M. 2022; 132 (4)

  View details for DOI 10.1063/5.0096686

  View details for Web of Science ID 000830587700007

• Nonvolatile Ferroelastic Strain from Flexoelectric Internal Bias Engineering PHYSICAL REVIEW APPLIED Hou, W., Chowdhury, S. A., Dey, A., Watson, C., Pena, T., Azizimanesh, A., Askari, H., Wu, S. M. 2022; 17 (2)

  View details for DOI 10.1103/PhysRevApplied.17.024013

  View details for Web of Science ID 000753521800001

• Temperature and time stability of process-induced strain engineering on 2D materials JOURNAL OF APPLIED PHYSICS Pena, T., Azizimanesh, A., Qiu, L., Mukherjee, A., Vamivakas, A., Wu, S. M. 2022; 131 (2)

  View details for DOI 10.1063/5.0075917

  View details for Web of Science ID 000746515900005

• Mechanical Properties and Strain Transfer Behavior of Molybdenum Ditelluride (MoTe2) Thin Films JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME Chowdhury, S., Inzani, K., Pena, T., Dey, A., Wu, S. M., Griffin, S. M., Askari, H. 2022; 144 (1)

  View details for DOI 10.1115/1.4051306

  View details for Web of Science ID 000720347600002

• Strain engineering 2D MoS2 with thin film stress capping layers 2D MATERIALS Pena, T., Chowdhury, S. A., Azizimanesh, A., Sewaket, A., Askari, H., Wu, S. M. 2021; 8 (4)

  View details for DOI 10.1088/2053-1583/ac08f2

  View details for Web of Science ID 000672331000001

• Uniaxial and biaxial strain engineering in 2D MoS2 with lithographically patterned thin film stressors APPLIED PHYSICS LETTERS Azizimanesh, A., Pena, T., Sewaket, A., Hou, W., Wu, S. M. 2021; 118 (21)

  View details for DOI 10.1063/5.0049446

  View details for Web of Science ID 000681664200001

• Strain tuning of the emission axis of quantum emitters in an atomically thin semiconductor OPTICA Chakraborty, C., Mukherjee, A., Moon, H., Konthasinghe, K., Qiu, L., Hou, W., Pena, T., Watson, C., Wu, S. M., Englund, D., Vamivakas, N. 2020; 7 (6): 580-585

  View details for DOI 10.1364/OPTICA.377886

  View details for Web of Science ID 000550698300005

• Strain-based room-temperature non-volatile MoTe2 ferroelectric phase change transistor NATURE NANOTECHNOLOGY Hou, W., Azizimanesh, A., Sewaket, A., Pena, T., Watson, C., Liu, M., Askari, H., Wu, S. M. 2019; 14 (7): 668-+

  Abstract

  The primary mechanism of operation of almost all transistors today relies on the electric-field effect in a semiconducting channel to tune its conductivity from the conducting 'on' state to a non-conducting 'off' state. As transistors continue to scale down to increase computational performance, physical limitations from nanoscale field-effect operation begin to cause undesirable current leakage, which is detrimental to the continued advancement of computing1,2. Using a fundamentally different mechanism of operation, we show that through nanoscale strain engineering with thin films and ferroelectrics the transition metal dichalcogenide MoTe2 can be reversibly switched with electric-field-induced strain between the 1T'-MoTe2 (semimetallic) phase to a semiconducting MoTe2 phase in a field-effect transistor geometry. This alternative mechanism for transistor switching sidesteps all the static and dynamic power consumption problems in conventional field-effect transistors3,4. Using strain, we achieve large non-volatile changes in channel conductivity (Gon/Goff ≈ 107 versus Gon/Goff ≈ 0.04 in the control device) at room temperature. Ferroelectric devices offer the potential to reach sub-nanosecond non-volatile strain switching at the attojoule/bit level5-7, with immediate applications in ultrafast low-power non-volatile logic and memory8 while also transforming the landscape of computational architectures because conventional power, speed and volatility considerations for microelectronics may no longer exist.

  View details for DOI 10.1038/s41565-019-0466-2

  View details for Web of Science ID 000473760300017

  View details for PubMedID 31182837

• Pulsed, controlled, frequency-chirped laser light at GHz detunings for atomic physics experiments APPLIED PHYSICS B-LASERS AND OPTICS Kaufman, B., Paltoo, T., Grogan, T., Pena, T., St John, J. P., Wright, M. J. 2017; 123 (2)

  View details for DOI 10.1007/s00340-017-6649-3

  View details for Web of Science ID 000394290900007