Publications de Jun Ma | EPFL Graph Search

Deep-Learning Reconstruction for 7T MP2RAGE and SPACE MRI: Improving Image Quality at High Acceleration Factors

American Society of Neuroradiology (ASNR)2025

The multimodality cell segmentation challenge: toward universal solutions

Sahand Jamal Rahi, Vojislav Gligorovski, Marco Labagnara, Jun Ma, Maxime Emmanuel Scheder, Xin Yang, Yao Zhang, Bo Wang, Yixin Wang, Lin Han

Cell segmentation is a critical step for quantitative single-cell analysis in microscopy images. Existing cell segmentation methods are often tailored to specific modalities or require manual interventions to specify hyper-parameters in different experimen ...

Nature Portfolio2024

Bacterial inactivation in sunlit surface waters is dominated by reactive species that emanate from the synergy between light, iron, and natural organic matter

César Pulgarin, Stefanos Giannakis, Jun Ma, Da Wang, Shuang Song

In this study, the synergistic and antagonistic effects of Fe species and coexisting natural organic matter (NOM) on the efficacy of solar light disinfection of water are investigated. Different initial iron species (Fe2+/Fe3+) and naturalorganic matter ty ...

Elsevier2023

Multi-channel nanowire devices for efficient power conversion

Elison de Nazareth Matioli, Vasiliki Tileli, Jun Ma, Luca Nela, Catherine Erine, Tzu-Hsien Shen, Taifang Wang

Nanowire-based devices can potentially be of use in a variety of electronic applications, from ultrascaled digital circuits to 5G communication networks. However, the devices are typically restricted to low-power applications due to the relatively low elec ...

2021

P-GaN Tri-Gate MOS Structure for Normally-Off GaN Power Transistors

Elison de Nazareth Matioli, Jun Ma, Luca Nela, Catherine Erine, Minghua Zhu, Pirouz Sohi, Mohammad Samizadeh Nikooytabalvandani

In this letter, we present a new concept for normally-off AlGaN/GaN-on-Si MOS-HEMTs based on the combination of p-GaN, tri-gate and MOS structures to achieve high threshold voltage (V-TH) and low on-resistance (R-ON). The p-GaN is used to engineer the band ...

Institute of Electrical and Electronics Engineers2021

High-Performance Enhancement-Mode AlGaN/GaN Multi-Channel Power Transistors

Elison de Nazareth Matioli, Remco Franciscus Peter van Erp, Halil Kerim Yildirim, Jun Ma, Luca Nela, Catherine Erine

AlGaN/GaN devices have shown outstanding potential for power conversion applications. However, despite the recent progress, their performance is still far from what the material can offer in terms of on-resistance and breakdown voltage. To address this cha ...

IEEE2021

Ultra-compact, high-frequency power integrated circuits based on GaN-on-Si Schottky Barrier Diodes

Elison de Nazareth Matioli, Remco Franciscus Peter van Erp, Jun Ma, Luca Nela, Georgios Kampitsis

GaN transistors are being employed in an increasing number of applications thanks to their excellent performance and competitive price. Yet, GaN diodes are not commercially available and little is known about their performance and potential impact on power ...

2020

Investigation of p-GaN tri-Gate normally-Off GaN Power MOSHEMTs

Elison de Nazareth Matioli, Jun Ma, Minghua Zhu

In this work, we present the investigation of the combination of p-GaN gate and tri-gate structures to achieve normally-off operation on GaN-on-Si MOSFETs. We have developed and optimized a selective and low-damage p-GaN etching recipe to stop at the AlGaN ...

IEEE2020

High-Frequency GaN-on-Si power integrated circuits based on Tri-Anode SBDs

Elison de Nazareth Matioli, Remco Franciscus Peter van Erp, Jun Ma, Halil Kerim Yildirim, Luca Nela, Georgios Kampitsis

In this work, we report on the switching performance of AlGaN/GaN lateral Tri-Anode SBDs. The Tri-Anode architecture leads to a more than 50% reduction in the device charge with respect to conventional planar structure, confirmed both by capacitive and rev ...

IEEE2020

Multi-Channel AlGaN/GaN In-Plane-Gate Field-Effect Transistors

Elison de Nazareth Matioli, Jun Ma, Catherine Erine, Giovanni Santoruvo

In this letter, we present a multi-channel in-plane-gate field effect transistor (MC-IPGFET). In the proposed device, multiple vertically stacked two-dimensional electron gases (2DEGs) are simultaneously controlled by lateral in-plane gates formed with the ...

Institute of Electrical and Electronics Engineers2020