159 citations · 979 across the 14 of their papers we have counts for
14 papers
Reflective Metal/Semiconductor Tunnel Junctions for Hole Injection in AlGaN UV LEDs
Yuewei Zhang, Sriram Krishnamoorthy, Fatih Akyol +6
In this work, we investigate the use of nanoscale polarization engineering to achieve efficient hole injection from metals to ultra-wide band gap AlGaN, and we show that UV-reflect…
Tunnel-injected sub-260 nm ultraviolet light emitting diodes
Yuewei Zhang, Sriram Krishnamoorthy, Fatih Akyol +5
We report on tunnel-injected deep ultraviolet light emitting diodes (UV LEDs) configured with a polarization engineered Al0.75Ga0.25N/ In0.2Ga0.8N tunnel junction structure. Tunnel…
Design and Demonstration of Ultra Wide Bandgap AlGaN Tunnel Junctions
Yuewei Zhang, Sriram Krishnamoorthy, Fatih Akyol +4
Ultra violet light emitting diodes (UV LEDs) face critical limitations in both the injection efficiency and light extraction efficiency due to the resistive and absorbing p-type co…
AlGaN Channel Field Effect Transistors with Graded Heterostructure Ohmic Contacts
Sanyam Bajaj, Fatih Akyol, Sriram Krishnamoorthy +2
We report on ultra-wide bandgap (UWBG) Al0.75Ga0.25N channel metal-insulator-semiconductor field-effect transistors (MISFET) with heterostructure engineered low-resistance ohmic co…
Design of P-Type Cladding Layers for Tunnel-Injected UVA Light Emitting Diodes
Yuewei Zhang, Sriram Krishnamoorthy, Fatih Akyol +4
We discuss the engineering of p-AlGaN cladding layers for achieving efficient tunnel-injected III-Nitride ultraviolet light emitting diodes (UV LEDs) in the UV-A spectral range. We…
Low-resistance GaN tunnel homojunctions with 150 kA/cm^2 current and repeatable negative differential resistance
Fatih Akyol, Sriram Krishnamoorthy, Yuewei Zhang +3
We report GaN n++/p++ interband tunnel junctions with repeatable negative differential resistance and low resistance. Reverse and forward tunneling current densities were observed…
Enhanced Light Extraction in Tunnel Junction Enabled Top Emitting UV LEDs
Yuewei Zhang, Andrew Allerman, Sriram Krishnamoorthy +4
The efficiency of ultra violet LEDs is critically limited by the absorption losses in p-type and metal layers. In this work, surface roughening based light extraction structures ar…
Simulation of Enhancement Mode GaN HEMTs with Threshold > 5 V using P-type Buffer
Sanyam Bajaj, Fatih Akyol, Sriram Krishnamoorthy +2
A high threshold voltage enhancement-mode GaN HEMT with p-type doped buffer is discussed and simulated. Analytical expressions are derived to explain the role of buffer capacitance…
Density-Dependent Electron Transport and Precise Modeling of GaN HEMTs
Sanyam Bajaj, Omor F. Shoron, Pil Sung Park +7
We report on the direct measurement of two-dimensional sheet charge density dependence of electron transport in AlGaN/GaN high electron mobility transistors. Pulsed IV measurements…
Interband Tunneling for Hole Injection in III-Nitride Ultra-violet Emitters
Yuewei Zhang, Sriram Krishnamoorthy, Jared M. Johnson +6
Ultra-violet emitters have several applications in the areas of sensing, water purification, and data storage. While the III-Nitride semiconductor system has the band gap region ne…
Modeling of High Composition AlGaN Channel HEMTs with Large Threshold Voltage
Sanyam Bajaj, Ting-Hsiang Hung, Fatih Akyol +2
We report on the potential of high electron mobility transistors (HEMTs) consisting of high composition AlGaN channel and barrier layers for power switching applications. Detailed…
InGaN/GaN Tunnel Junctions For Hole Injection in GaN Light Emitting Diodes
Sriram Krishnamoorthy, Fatih Akyol, Siddharth Rajan
InGaN/GaN tunnel junction contacts were grown on top of an InGaN/GaN blue (450 nm) light emitting diode wafer using plasma assisted molecular beam epitaxy. The tunnel junction cont…
Low Resistance GaN/InGaN/GaN Tunnel Junctions
Sriram Krishnamoorthy, Fatih Akyol, Pil Sung Park +1
Enhanced interband tunnel injection of holes into a PN junction is demonstrated using P-GaN/InGaN/N-GaN tunnel junctions with a specific resistivity of 1.2 X 10-4 Ω cm2. The design…
Polarization-engineered GaN/InGaN/GaN tunnel diodes
Sriram Krishnamoorthy, Digbijoy N. Nath, Fatih Akyol +3
We report on the design and demonstration of polarization-engineered GaN/InGaN/GaN tunnel junction diodes with high current density and low tunneling turn-on voltage. Wentzel-Krame…