A new issue of #ACS Applied Materials & Interfaces (@ACS_AMI) is live! On the #cover an #article about #Leveraging Combinatorial #Sputtering to Investigate #Ferroelectric #Properties of the HfxZr1–xO2 System

Call for Papers | AIMS Materials Science
SI: Piezoelectric & Ferroelectric Materials

Topics: lead-free ceramics, polymers, composites, dielectrics, sensors, actuators, energy harvesters, devices.

Submit: www.aimspress.com/aimsmates/ar...

#Piezoelectric #Ferroelectric #MaterialsScience

[Open Access]
Data processing capability of polarization dynamics in ferroelectric-gate transistor-based physical reservoir computing
2025 Appl. Phys. Express 18 081001

iopscience.iop.org/article/10.3...

#APEX
#OpenAccess
#Physics
#ferroelectric
#FET
#computing
#HfO2
#nonlinearity

Toward high-layer 3D hafnia ferroelectric stacks for neuromorphic computing: manufacturing insights and integration challenges

This #IJEM study examines the critical #Manufacturing challenges and material insights necessary to integrate 3D hafnia #Ferroelectric stacks into next-generation #Neuromorphic hardware for high-density #NeuromorphicComputing.

#OpenAccess: doi.org/10.1088/2631...

[2025 OPEN ACCESS]
Voltage-mode reservoir computing with ferroelectric CMOS inverters
2025 Appl. Phys. Express 18 061002

iopscience.iop.org/article/10.3...

#APEX
#OA
#オープンアクセス
#Physics
#Reservoir
#Computing
#Ferroelectric
#FET
#AI
#CMOS
#Technology
#Prediction
#Energy
#Efficiency

[2025 OPEN ACCESS]
Effect of pretilt-induced symmetry-breaking on the polarization distribution of polar nematic liquid crystals
2025 Appl. Phys. Express 18 045502

iopscience.iop.org/article/10.3...

#APEX
#OpenAccess
#Physics
#liquid
#crystals
#ferroelectric
#nematic
#molecular
#orientation

Tackling #ferroelectric scaling dilemmas for AI-era computing!

A #PKUResearch team reports wafer-scale, uniform, ultrathin van der Waals ferroelectric oxide Bi₂SeO₅—retaining robust ferroelectricity down to monolayer thickness on a parent 2D semiconductor Bi₂O₂Se substrate.

#FeFET @science.org

[Progress Review]
Integration of ferroelectric devices for advanced in-memory computing concepts
2024 Jpn. J. Appl. Phys. 63 050802

iopscience.iop.org/article/10.3...

#JJAP
#physics
#Openaccess
#Review
#Memory
#Ferroelectric
#Neuromorphic
#FeFET
#FeMFET

[2025 Open Access]
Magnetism control of thin CoFeB layers by ferroelectric polarization
2025 Appl. Phys. Express 18 033003

iopscience.iop.org/article/10.3...

#APEX
#OpenAccess
#Physics
#magnetism
#perpendicular
#magnetic
#anisotropy
#ferroelectric
#polarization
#coercivity
#MOKE

New #ultrathin #ferroelectric #capacitors show promise for #compact #memory #devices

Researchers built a ferroelectric capacitor just 30 nm thick including electrodes. Using (Al,Sc)N, it enables high-density on-chip memory and efficient electronics scitechupdates.com/n...

[Latest Article: Open Access]
Tunable visible-light shift current in strain-engineered ferroelectric perovskite CsPbI3
2025 Appl. Phys. Express 18 121001

iopscience.iop.org/article/10.3...

#APEX
#OpenAccess
#Physics
#photovoltaic
#ferroelectric
#halide
#perovskite
#engineering
#polarization

[Open Access]
Impact of aluminum concentration variations on the performance of thin barrier enhancement-mode GaN MIS-HEMTs
2025 Jpn. J. Appl. Phys. 64 01SP18

iopscience.iop.org/article/10.3...

#JJAP
#physics
#Openaccess
#AlGaN
#GaN
#HEMT
#ferroelectric
#thin
#barrier

[Spotlights 2023]
Local atomic structure of V-doped BiFeO3 thin films measured by X-ray fluorescence holography
2023 Jpn. J. Appl. Phys. 62 SM1017

iopscience.iop.org/article/10.3...

#JJAP
#physics
#BIFeO3
#ferroelectric
#Xray
#fluorescence
#holography

[Open Access]
Origin of the ultrahigh field-induced strain in the Gd-doped 0.854Bi0.5Na0.5TiO3-0.12Bi0.5K0.5TiO3-0.026BaTiO3 ternary ceramic system
2024 Jpn. J. Appl. Phys. 63 09SP13

iopscience.iop.org/article/10.3...

#JJAP
#physics
#Openaccess
#piezoelectric
#ferroelectric
#strain
#BNT
#BKT
#BT

Ferroelectric Innovation Shatters Performance Barriers in GaN Power Electronics Negative capacitance has the potential to improve GaN device performance and open new possibilities in power electronics and telecommunications.

Integrating #ferroelectric materials with negative-capacitance properties into #GaN transistors can improve performance.

[PROGRESS REVIEW 2023 Open Access]
Reliability of piezoelectric films for MEMS
2023 Jpn. J. Appl. Phys. 62 SM0802

iopscience.iop.org/article/10.3...

#JJAP
#physics
#Openaccess
#ferroelectric
#reliability
#piezo
#MEMS

[Open access]
Impact of ambient moisture on gate controllability in ferroelectric-gate field-effect transistors with bottom-gate geometry
2024 Jpn. J. Appl. Phys. 63 08SP06

iopscience.iop.org/article/10.3...

#JJAP
#physics
#Openaccess
#ferroelectric
#FET
#oxide
#ambient
#degradation
#chemical

2024 OPEN ACCESS
Enhancement of remnant polarization in ferroelectric HfO2 thin films induced by mechanical uniaxial tensile strain after the crystallization process
2024 17 051003

iopscience.iop.org/article/10.3...

#APEX
#Physics
#OpenAccess
#polarization
#ferroelectric
#crystallization

"What if a simple twist could unlock new tech? Researchers found that pressing a special boron nitride form creates a unique ferroelectric effect, paving the way for exciting nanoscale applications. What potential uses do you see? #Ferroelectric #Innovation #EmergingTech" LINK

[PROGRESS REVIEW 2023 Open Access]
Advances in development of Pb-free piezoelectric materials for transducer applications
2023 Jpn. J. Appl. Phys. 62 SJ0801

iopscience.iop.org/article/10.3...

#JJAP
#physics
#Openaccess
#Piezoelectric
#Ferroelectric
#Ultrasound
#Transducer
#Actuator

[2024 Open Access]
Impact of CeOx layer insertion on ferroelectric properties of Hf-Zr-O films prepared by chemical solution deposition
2024 Jpn. J. Appl. Phys. 63 01SP23

iopscience.iop.org/article/10.3...

#JJAP
#physics
#Openaccess
#ferroelectric
#thinfilms
#HZO
#HfO2
#CeOx
#multivalent
#oxide

Energy‑Convergence Trade‑Off in Bio‑Inspired Neural Network Training

Ferroelectric HfO₂/ZrO₂ memristive synapses trained with 20 ns pulses cut per‑update energy, though more epochs were needed; mixed‑precision updates still gave higher accuracy. getnews.me/energy-convergence-trade... #ferroelectric #memristor

[2024 OPEN ACCESS]
Evaluation of polar alignment structure and surface anchoring energy in ferroelectric nematic liquid crystals by renormalized transmission spectroscopic ellipsometry
2024 17 031001

iopscience.iop.org/article/10.3...

#APEX
#Physics
#ferroelectric
#spectroscopy

Piezoresponse force microscopy brainrot #PFM #AFM #ferroelectric #piezoelectric www.nature.com/articles/s41...

Improving SiC MOSFET Short-Circuit Performance with a Ferroelectric Gate Stack This novel approach does not require any change to the fundamental design, layout, or control circuitry of the SiC MOSFET.

This novel approach does not require any change to the fundamental design, layout, or control circuitry of the #SiC #MOSFET. #Ferroelectric

Original post on semiengineering.com

Reconfigurable Single-Walled CNT FeFET (Univ. of Pennsylvania, Yonsei et al.) A new technical paper titled “Reconfigurable single-walled carbon nanotube ferroelectric field-effect transistors” ...

#Materials #Technical #Papers #Transistors #carbon […]

[Original post on semiengineering.com]

[Latest Article : Open Access]
Data processing capability of polarization dynamics in ferroelectric-gate transistor-based physical reservoir computing
2025 Appl. Phys. Express 18 081001

iopscience.iop.org/article/10.3...

#APEX
#OpenAccess
#Physics
#ferroelectric
#FET
#computing
#HfO2
#nonlinearity

[Open Access]
Origin of the ultrahigh field-induced strain in the Gd-doped 0.854Bi0.5Na0.5TiO3-0.12Bi0.5K0.5TiO3-0.026BaTiO3 ternary ceramic system
2024 Jpn. J. Appl. Phys. 63 09SP13

iopscience.iop.org/article/10.3...

#JJAP
#physics
#Openaccess
#piezoelectric
#ferroelectric
#strain
#BNT
#BKT
#BT

Ferroelectric Helps Break Transistor Limits Integrating an electronic material that exhibits a strange property called negative capacitance can help high-power gallium nitride transistors break through a performance barrier, say scientists in California. Research published in _Science_ suggests that negative capacitance helps sidestep a physical limit that typically enforces trade-offs between how well a transistor performs in the “on” state versus how well it does in the “off” state. The researchers behind the project say this shows that negative capacitance, which has been extensively studied in silicon, may have broader applications than previously appreciated. Electronics based on GaN power 5G base stations and compact power adapters for cellphones. When trying to push the technology to higher frequency and higher power operations, engineers face trade-offs. In GaN devices used to amplify radio signals, called high-electron-mobility transistors (HEMTs), adding an insulating layer called a dielectric prevents them from wasting energy when they’re turned off, but it also suppresses the current flowing through them when they are on, compromising their performance. To maximize energy efficiency and switching speed, HEMTs use a metal component called a Schottky gate, which is set directly on top of a structure made up of layers of GaN and aluminum gallium nitride. When a voltage is applied by the Schottky gate, a 2D electron cloud forms inside the transistor. These electrons are zippy and help the transistor switch rapidly, but they also tend to travel up toward the gate and leak out. To prevent them from escaping, the device can be capped with a dielectric. But this additional layer increases the distance between the gate and the electron cloud. And that distance decreases the ability of the gate to control the transistor, hampering performance. This inverse relationship between the degree of gate control and the thickness of the device is called the Schottky limit. “Getting more current from the device by adding an insulator is extremely valuable. This cannot be achieved in other cases without negative capacitance.” —Umesh Mishra, UC Santa Barbara In place of a conventional dielectric, Sayeef Salahuddin, Asir Intisar Khan, and Urmita Sikderan, electrical engineers at University of California, Berkeley, collaborated with researchers at Stanford University to test a special coating on GaN devices with Schottky gates. This coating is made up of a hafnium oxide layer frosted with a thin topping of zirconia oxide. The 1.8-nanometer-thick bilayer material is called HZO for short, and it’s engineered to display negative capacitance. HZO is a ferroelectric. That is, it has a crystal structure that allows it to maintain an internal electrical field even when no external voltage is applied. (Conventional dielectrics don’t have this inherent electrical field.) When a voltage is applied to the transistor, HZO’s inherent electric field opposes it. In a transistor, this leads to a counterintuitive effect: A decrease in voltage causes an increase in the charge stored in HZO. This negative capacitance response effectively amplifies the gate control, helping the transistor’s 2D electron cloud accumulate charge and boosting the on-state current. At the same time, the thickness of the HZO dielectric suppresses leakage current when the device is off, saving energy. “When you put another material, the thickness should go up, and the gate control should go down,” Salahuddin says. However, the HZO dielectric seems to break the Schottky limit. “This is not conventionally achievable,” he says. “Getting more current from the device by adding an insulator is extremely valuable,” says Umesh Mishra, a specialist in GaN high-electron-mobility transistors at the University of California, Santa Barbara, who was not involved with the research. “This cannot be achieved in other cases without negative capacitance.” Leakage current is a well-known problem in these kinds of transistors, “so integrating an innovative ferroelectric layer into the gate stack to address this has clear promise,” says Aaron Franklin, an electrical engineer at Duke University, in Durham, N.C. “It certainly is an exciting and creative advancement.” ## Going Further With Negative Capacitance Salahuddin says the team is currently seeking industry collaborations to test the negative capacitance effect in more advanced GaN radio-frequency transistors. “What we see scientifically breaks a barrier,” he says. Now that they can break down the Schottky limit in GaN transistors under lab conditions, he says, they need to test whether it works in the real world. Mishra agrees, noting that the devices described in the paper are relatively large. “It will be great to see this in a device that’s highly scaled,” says Mishra. “That’s where this will really shine.” He says the work is “a great first step.” Salahuddin has been studying negative capacitance in silicon transistors since 2007. And for much of that time, says Mishra, Salahuddin has been subject to intense questioning after every conference presentation. Nearly 20 years later, Salahuddin’s team has made a strong case for the physics of negative capacitance, and the GaN work shows it may help push power electronics and telecom equipment to higher powers in the future, says Mishra. The Berkeley team also hopes to test the effect in transistors made from other kinds of semiconductors including diamond, silicon carbide, and other materials.

Ferroelectric Helps Break Transistor Limits Integrating an electronic material that exhibits a strange property called negative capacitance can help high-power gallium nitride transistors break through a performance barrier, say scientists in California. Research published in _Science_ suggests that negative capacitance helps sidestep a physical limit that typically enforces trade-offs between how well a transistor performs in the “on” state versus how well it does in the “off” state. The researchers behind the project say this shows that negative capacitance, which has been extensively studied in silicon, may have broader applications than previously appreciated. Electronics based on GaN power 5G base stations and compact power adapters for cellphones. When trying to push the technology to higher frequency and higher power operations, engineers face trade-offs. In GaN devices used to amplify radio signals, called high-electron-mobility transistors (HEMTs), adding an insulating layer called a dielectric prevents them from wasting energy when they’re turned off, but it also suppresses the current flowing through them when they are on, compromising their performance. To maximize energy efficiency and switching speed, HEMTs use a metal component called a Schottky gate, which is set directly on top of a structure made up of layers of GaN and aluminum gallium nitride. When a voltage is applied by the Schottky gate, a 2D electron cloud forms inside the transistor. These electrons are zippy and help the transistor switch rapidly, but they also tend to travel up toward the gate and leak out. To prevent them from escaping, the device can be capped with a dielectric. But this additional layer increases the distance between the gate and the electron cloud. And that distance decreases the ability of the gate to control the transistor, hampering performance. This inverse relationship between the degree of gate control and the thickness of the device is called the Schottky limit. “Getting more current from the device by adding an insulator is extremely valuable. This cannot be achieved in other cases without negative capacitance.” **—Umesh Mishra, University of California, Santa Barbara** In place of a conventional dielectric, Sayeef Salahuddin, Asir Intisar Khan, and Urmita Sikderan, electrical engineers at University of California, Berkeley, collaborated with researchers at Stanford University to test a special coating on GaN devices with Schottky gates. This coating is made up of a hafnium oxide layer frosted with a thin topping of zirconia oxide. The 1.8-nanometer-thick bilayer material is called HZO for short, and it’s engineered to display negative capacitance. HZO is a ferroelectric. That is, it has a crystal structure that allows it to maintain an internal electrical field even when no external voltage is applied. (Conventional dielectrics don’t have this inherent electrical field.) When a voltage is applied to the transistor, HZO’s inherent electric field opposes it. In a transistor, this leads to a counterintuitive effect: A decrease in voltage causes an increase in the charge stored in HZO. This negative capacitance response effectively amplifies the gate control, helping the transistor’s 2D electron cloud accumulate charge and boosting the on-state current. At the same time, the thickness of the HZO dielectric suppresses leakage current when the device is off, saving energy. “When you put another material, the thickness should go up, and the gate control should go down,” Salahuddin says. However, the HZO dielectric seems to break the Schottky limit. “This is not conventionally achievable,” he says. “Getting more current from the device by adding an insulator is extremely valuable,” says Umesh Mishra, a specialist in GaN high-electron-mobility transistors at the University of California, Santa Barbara, who was not involved with the research. “This cannot be achieved in other cases without negative capacitance.” Leakage current is a well-known problem in these kinds of transistors, “so integrating an innovative ferroelectric layer into the gate stack to address this has clear promise,” says Aaron Franklin, an electrical engineer at Duke University, in Durham, N.C. “It certainly is an exciting and creative advancement.” ## Going Further With Negative Capacitance Salahuddin says the team is currently seeking industry collaborations to test the negative capacitance effect in more advanced GaN radio-frequency transistors. “What we see scientifically breaks a barrier,” he says. Now that they can break down the Schottky limit in GaN transistors under lab conditions, he says, they need to test whether it works in the real world. Mishra agrees, noting that the devices described in the paper are relatively large. “It will be great to see this in a device that’s highly scaled,” says Mishra. “That’s where this will really shine.” He says the work is “a great first step.” Salahuddin has been studying negative capacitance in silicon transistors since 2007. And for much of that time, says Mishra, Salahuddin has been subject to intense questioning after every conference presentation. Nearly 20 years later, Salahuddin’s team has made a strong case for the physics of negative capacitance, and the GaN work shows it may help push power electronics and telecom equipment to higher powers in the future, says Mishra. The Berkeley team also hopes to test the effect in transistors made from other kinds of semiconductors including diamond, silicon carbide, and other materials.