Gate leakage suppression in p-GaN/AlGaN p-channel transistors via transferred BN gate dielectric for high-temperature operation Cheng Chang, Chenyang Lin, Shisong Luo, Huayi Chen, Chufan Qiu, Lucas Lau, Zonghao Zhang, Tao Li, Md Jahidul Hoq Emon, Rummanur Rahad, Jun Lou, Yuji Zhao Applied Physics Letters, 2026 In this Letter, we report gate leakage suppression in p-GaN/AlGaN p-channel transistors enabled by a transferred boron nitride (BN) gate dielectric for high-temperature operation. To elucidate the impact of BN integration, we systematically compare transfer characteristics, transconductance, and related metrics as functions of temperature (25–300 °C) for BN and conventional Schottky gate devices. Notably, current density in the BN device remains stable above ∼3 mA/mm at 300 °C, with an on/off ratio >103 and ID, max × LDS reaching ∼47 μA. At the same time, both the threshold voltage shift and the subthreshold slope show minimal variation, highlighting the excellent stability of this device. These results can provide insight into design strategies for high-temperature p-GaN p-channel transistors.
Ultrawide bandgap semiconductors for photonic applications: recent advances in epitaxial Ga2O3, hBN, and ScAlN [Invited] Tao Li, Md Jahidul Hoq Emon, Rummanur Rahad, Arka Chatterjee, Vijay Dalakoti, Jiangnan Liu, Huabin Yu, Zetian Mi, Shengxi Huang, Yuji Zhao Optical Materials Express, 2025 The epitaxial growth of semiconductor materials plays a pivotal role in photonic applications by enabling precise control over material composition and facilitating flexible heterogeneous integration. Sophisticated epitaxial techniques have been extensively developed for mature, narrow-bandgap semiconductor platforms such as silicon (Si) and indium phosphide (InP), which have laid the foundation for photonic integrated circuits (PICs) used in data centers and optical communication systems. In contrast, the epitaxial growth of emerging ultrawide-bandgap (UWBG) semiconductors and the exploration of their potential for photonic applications remain an active area of research. This review summarizes recent progress in the epitaxial growth, optical properties, and photonic applications of three representative UWBG semiconductors: gallium oxide (Ga2O3), hexagonal boron nitride (hBN), and scandium aluminum nitride (ScAlN). For each material, we review state-of-the-art epitaxial growth techniques, optical properties across linear, nonlinear, and quantum optical regimes, and unique application opportunities that arise from these properties. This review aims to provide a timely broadband resource for researchers interested in advancing the field of epitaxial UWBG semiconductors for photonics.
Mitigation of self-heating in AlGaN/GaN HEMTs using transferred LPCVD-grown h-BN Cheng Chang, Kad Dokwan Kook, Chenyang Lin, Xiang Zhang, Yuetong Yang, Shisong Luo, Ziyi He, Tao Li, Mingfei Xu, Lucas Lau, Md Jahidul Hoq Emon, Rummanur Rahad, Pulickel Ajayan, Jun Lou, Satish Kumar, Yuji Zhao Applied Physics Letters, 2025 With the increasing power density of GaN-based power devices, the self-heating effect has become a significant bottleneck, impacting device reliability and performance, which makes effective thermal management essential. Hexagonal boron nitride (h-BN), with its high thermal conductivity and excellent electrical insulation, offers a promising solution for heat dissipation. In this Letter, we demonstrate that the transferred low-pressure chemical vapor deposition-grown h-BN effectively mitigates self-heating in AlGaN/gallium nitride high electron mobility transistors. All 12 tested devices showed increased current after BN transfer. The average current density in the saturation region improved from 819 to 924 mA/mm, and the current retention rose from 89% to 98%. Thermo-reflectance measurements revealed a significant reduction in channel temperature from 179 to 115 °C under a power density of 21 W/mm. The improvement is attributed to the high in-plane thermal conductivity of h-BN, which is proven by the hotspot models. This approach shows promise as a practical method to reduce self-heating and enhance the thermal reliability of GaN-based power transistors.
Miniaturized Plasmonic Sensor With Dual-Function Capability for Pressure and Flow Rate Detection at Subwavelength Levels Rummanur Rahad, Joyonta Das Joy, Md. Shakibur Rahman, Md Jahidul Hoq Emon, Mohammad Ashraful Haque IEEE Sensors Journal, 2025 This paper introduces a nanoscale plasmonic sensor with dual-function capabilities for detecting both pressure and flow rate, designed using a metal-insulator-metal (MIM) bus waveguide coupled with a resonator featuring a horizontal slot and multiple stubs. The sensor demonstrates high pressure sensitivity, achieving 1100.70 nm/MPa for pressure detection, with a Figure of Merit (FOM) of 4.6054, and effectively measures flow rates from 58.544 pL/s to 356.43 pL/s using an optical spectrum analyzer (OSA). Finite Element Method (FEM) simulations were employed to analyze the pressure-induced wavelength shifts, enhancing the sensor’s versatility in integrated sensing applications. The sensor’s compact footprint, simplicity, and ease of fabrication make it ideal for integration into lab-on-a-chip devices. Its dual functionality provides a novel solution for precise, real-time monitoring in biomedical and microfluidic engineering applications.
Visible Spectrum Topological Photonic Crystal Cavities on the III-N Wide Bandgap Platform Tao Li, Wenjing Wu, Cheng Chang, Shisong Luo, Mingfei Xu, Ziyi He, Md. Jahidul Hoq Emon, Rummanur Rahad, Lucas Lau, Shengxi Huang, Yuji Zhao CLEO Fundamental Science Proceedings CLEO 2025, 2025 GaN-based topological photonic crystal cavities resonating near the wavelength of 680 nm were experimentally demonstrated with a high Q-factor near 600. Further resonance extension covering the entire visible spectrum was achieved through structure scaling.
Explainable Transfer Learning for Precise Alzheimer's Disease Prediction from MRI Data Mahin Khan Mahadi, Jamal Uddin, Md. Zidan Shahriar, Rummanur Rahad, A.M. Tamim Haider, Rashed Hasan Ratul, Ahmad Shafiullah, Asif Newaz, Ashik Ahmed 2024 International Conference on Innovations in Science Engineering and Technology Innovative Technologies for Global Solutions Iciset 2024, 2024
Gate leakage suppression in p-GaN/AlGaN p-channel transistors via transferred BN gate dielectric for high-temperature operation C Chang, C Lin, S Luo, H Chen, C Qiu, L Lau, Z Zhang, T Li, MJH Emon, ... Applied Physics Letters 128 (20) , 2026 2026
Dual-mode CMOS-compatible optically tunable plasmonic sensor with symmetrical cavity for simultaneous and independent monitoring of pressure and temperature deviations from … R Rahad, JD Joy, MS Rahman, MJH Emon, R Rahad, MK Mahadi Surfaces and Interfaces, 108325 , 2025 2025
Detection of fuel adulteration levels in diesel by analyzing the shape changes of ultrashort pulses transmitted through hollow-core PCF sensor A Al Mahmud Nafiz, SM Mahbub, AA Protiva, M Tamim, RH Sagor, ... The European Physical Journal Plus 140 (11), 1146 , 2025 2025 Citations: 1
Highly sensitive temperature sensor based on tunable stoichiometric alternative plasmonic material using multiple thermo-responsive analytes MS Rahman, R Rahad, DM Rahman, MJH Emon, R Rahad Measurement 258, 119127 , 2025 2025 Citations: 3
Refractory Transition Metal Nitride-Based CMOS-Compatible Plasmonic Sensor for Brain Tissue Differentiation and Tumor Detection MS Rahman, JD Joy, R Rahad, MH Chowdhury, MI Reja, A Chowdhury, ... IEEE Transactions on Components, Packaging and Manufacturing Technology , 2025 2025
Ultrawide bandgap semiconductors for photonic applications: recent advances in epitaxial Ga 2 O 3 , hBN, and ScAlN T Li, MJH Emon, R Rahad, A Chatterjee, V Dalakoti, J Liu, H Yu, Z Mi, ... Optical Materials Express 15 (10), 2383-2436 , 2025 2025 Citations: 3
Mitigation of self-heating in AlGaN/GaN HEMTs using transferred LPCVD-grown h-BN C Chang, KD Kook, C Lin, X Zhang, Y Yang, S Luo, Z He, T Li, M Xu, ... Applied Physics Letters 127 (8) , 2025 2025 Citations: 6
Visible Spectrum Topological Photonic Crystal Cavities on the III-N Wide Bandgap Platform T Li, W Wu, C Chang, S Luo, M Xu, Z He, MJH Emon, R Rahad, L Lau, ... CLEO: Fundamental Science, FF125_6 , 2025 2025
Miniaturized Plasmonic Sensor With Dual-Function Capability for Pressure and Flow Rate Detection at Subwavelength Levels R Rahad, JD Joy, MS Rahman, MJH Emon, MA Haque IEEE Sensors Journal , 2025 2025 Citations: 33
The Potential of Heavily Doped n-Type Silicon in Plasmonic Sensors JD Joy, MS Rahman, R Rahad, MH Chowdhury Measurement 242, 116049 , 2025 2025 Citations: 7
A phishing detection approach for empowering cybersecurity with explainable ai and selectkbest MK Mahadi, R Rahad, MZ Shahriar, R Debnath, FN Rahman, AMT Haider, ... 2024 27th International Conference on Computer and Information Technology … , 2024 2024 Citations: 1
A Novel and Effective Oxidation-Resistant Approach in Plasmonic MIM Biosensors for Real-Time Detection of Urea and Glucose in Urine for Monitoring Diabetic and Kidney Disease … JD Joy, MS Rahman, R Rahad, A Chowdhury, MH Chowdhury Optics Communications 573, 131012 , 2024 2024 Citations: 22
CMOS-Compatible Plasmonic Magnetic Field Sensor: An Alternative Approach Using Ultra-Compact MIM Configuration MA Haque, R Rahad, MO Faruque, ASM Mohsin Photonics and Nanostructures-Fundamentals and Applications 62, 101319 , 2024 2024 Citations: 16
Gated Recurrent Unit (GRU)-Based Deep Learning Method for Spectrum Estimation and Inverse Modeling in Plasmonic Devices MK Mahadi, R Rahad, MA Haque, MM Nishat Applied Physics A 130 (11), 784 , 2024 2024 Citations: 21
Explainable Transfer Learning for Precise Alzheimer’s Disease Prediction from MRI Data MK Mahadi, J Uddin, MZ Shahriar, R Rahad, AMT Haider, RH Ratul, ... 2024 International Conference on Innovations in Science, Engineering and … , 2024 2024 Citations: 1
Ultra-Short Pulse: A Comprehensive Way of Sensing Pure Solvents Through Hollow Core Photonic Crystal Fiber Sensor SM Mahbub, AAM Nafiz, AA Protiva, M Tamim, R Rahad Optical Materials 156, 116028 , 2024 2024 Citations: 17
Optical computing at the subwavelength scale: a multifunctional MIM plasmonic logic gate MA Haque, R Rahad, MO Faruque Applied Optics 63 (24), 6364-6370 , 2024 2024 Citations: 39
An Alternative Plasmonic Material-based CMOS-compatible Temperature Sensor R Rahad, MM Sobhani, MJH Emon, SMTS Afrid, MK Mahadi, ASM Mohsin, ... Optics Communications, 130749 , 2024 2024 Citations: 63
A Polarization Independent Highly Sensitive Metasurface-Based Biosensor for Lab-on-Chip Applications R Rahad, MA Haque, MK Mahadi, MO Faruque, SMTS Afrid, ASM Mohsin, ... Measurement 231, 114652 , 2024 2024 Citations: 98
Highly Sensitive Optically Tunable Transition Metal Nitride-Based Plasmonic Pressure Sensor With CMOS-Compatibility at Compact Subwavelength Dimensions R Rahad, MA Haque, MK Mahadi, ASM Mohsin, MO Faruque, SMTS Afrid, ... IEEE Sensors Journal , 2024 2024 Citations: 63
MOST CITED SCHOLAR PUBLICATIONS
Plasmonic Refractive Index Sensing in the Early Diagnosis of Diabetes, Anemia, and Cancer: An Exploration of Biological Biomarkers R Rahad, AKM Rakib, MA Haque, SS Sharar, RH Sagor Results in Physics 49, 106478 , 2023 2023 Citations: 151
A Novel Plasmonic MIM Sensor Using Integrated 1×2 Demultiplexer for Individual Lab-on-Chip Detection of Human Blood Group and Diabetes Level in the Visible to Near-Infrared Region R Rahad, MA Haque, MO Faruque, ASM Mohsin, MS Mobassir, RH Sagor IEEE Sensors Journal , 2024 2024 Citations: 103
Graphene-Metamaterial Based Tunable Broadband Polarization Insensitive Absorber for Terahertz Antenna Design R Rahad, ASM Mohsin, B Bhuian, MM Rahman IEEE Access , 2024 2024 Citations: 100
A Polarization Independent Highly Sensitive Metasurface-Based Biosensor for Lab-on-Chip Applications R Rahad, MA Haque, MK Mahadi, MO Faruque, SMTS Afrid, ASM Mohsin, ... Measurement 231, 114652 , 2024 2024 Citations: 98
Fuel Classification and Adulteration Detection Using a Highly Sensitive Plasmonic Sensor R Rahad, AKM Rakib, MK Mahadi, MO Faruque Sensing and Bio-Sensing Research 40, 100560 , 2023 2023 Citations: 83
ZrN-Based Plasmonic Sensor: A Promising Alternative to Traditional Noble Metal-Based Sensors for CMOS-Compatible and Tunable Optical Properties AKM Rakib, R Rahad, MO Faruque, RH Sagor Optics Express 31 (15), 25280-25297 , 2023 2023 Citations: 82
An Alternative Plasmonic Material-based CMOS-compatible Temperature Sensor R Rahad, MM Sobhani, MJH Emon, SMTS Afrid, MK Mahadi, ASM Mohsin, ... Optics Communications, 130749 , 2024 2024 Citations: 63
Highly Sensitive Optically Tunable Transition Metal Nitride-Based Plasmonic Pressure Sensor With CMOS-Compatibility at Compact Subwavelength Dimensions R Rahad, MA Haque, MK Mahadi, ASM Mohsin, MO Faruque, SMTS Afrid, ... IEEE Sensors Journal , 2024 2024 Citations: 63
Numerical Analysis of a Metal-Insulator-Metal Waveguide-Integrated Magnetic Field Sensor Operating at Sub-Wavelength Scales MA Haque, R Rahad, MO Faruque, MS Mobassir, RH Sagor Sensing and Bio-Sensing Research 43, 100618 , 2024 2024 Citations: 51
Plasmonic Sensor for Rapid Detection of Water Adulteration in Honey and Quantitative Measurement of Lactose Concentration in Solution MA Haque, R Rahad, AKM Rakib, SS Sharar, RH Sagor Results in Physics 51, 106733 , 2023 2023 Citations: 44
Optical computing at the subwavelength scale: a multifunctional MIM plasmonic logic gate MA Haque, R Rahad, MO Faruque Applied Optics 63 (24), 6364-6370 , 2024 2024 Citations: 39
Miniaturized Plasmonic Sensor With Dual-Function Capability for Pressure and Flow Rate Detection at Subwavelength Levels R Rahad, JD Joy, MS Rahman, MJH Emon, MA Haque IEEE Sensors Journal , 2025 2025 Citations: 33
Label-Free Biosensor on Chip (BoC) Based on Localized Surface Plasmon Resonance for Monitoring Temperature and Blood Hemoglobin Concentration S Mondal, ASM Mohsin, MBH Bhuian, MM Rahman, R Rahad Physica Scripta 99 (4), 045030 , 2024 2024 Citations: 32
A numerical investigation of the opposing-face semi circular refractive index sensor for detection of chemical pollutants and heavy metals in water SS Sharar, R Rahad, MA Haque, RH Sagor Optics Communications 549, 129887 , 2023 2023 Citations: 24
A Novel and Effective Oxidation-Resistant Approach in Plasmonic MIM Biosensors for Real-Time Detection of Urea and Glucose in Urine for Monitoring Diabetic and Kidney Disease … JD Joy, MS Rahman, R Rahad, A Chowdhury, MH Chowdhury Optics Communications 573, 131012 , 2024 2024 Citations: 22
Gated Recurrent Unit (GRU)-Based Deep Learning Method for Spectrum Estimation and Inverse Modeling in Plasmonic Devices MK Mahadi, R Rahad, MA Haque, MM Nishat Applied Physics A 130 (11), 784 , 2024 2024 Citations: 21
Ultra-Short Pulse: A Comprehensive Way of Sensing Pure Solvents Through Hollow Core Photonic Crystal Fiber Sensor SM Mahbub, AAM Nafiz, AA Protiva, M Tamim, R Rahad Optical Materials 156, 116028 , 2024 2024 Citations: 17
Understanding machine learning & its application in obesity estimation by explainable AI MK Mahadi, R Rahad, A Noman, S Ishrat, F Faisal 2024 International Conference on Inventive Computation Technologies (ICICT … , 2024 2024 Citations: 17
CMOS-Compatible Plasmonic Magnetic Field Sensor: An Alternative Approach Using Ultra-Compact MIM Configuration MA Haque, R Rahad, MO Faruque, ASM Mohsin Photonics and Nanostructures-Fundamentals and Applications 62, 101319 , 2024 2024 Citations: 16
The Potential of Heavily Doped n-Type Silicon in Plasmonic Sensors JD Joy, MS Rahman, R Rahad, MH Chowdhury Measurement 242, 116049 , 2025 2025 Citations: 7