| ||Wide Bandgap Semiconductor Laboratory||Boston University|
|The Wide Bandgap Semiconductor Laboratory is a state-of-the-art facility dedicated to studying the growth, fundamental material properties, and fabrication of novel electronic and opto-electronic devices. The lab specializes in III-nitride growth by Molecular Beam Epitaxy(MBE) and Hydride Vapor Phase Epitaxy(HVPE). It has a history in the development of LEDs and currently continues to focus on LEDs and semiconductor lasers in the blue-UV region of the electromagnetic spectrum.
| ||Visible and UV LEDs:|| ||This research aims at developing efficient blue/UV LEDs for solid state lighting as well as for detection of chemical and biological agents by excitation of their fluorescence.|
| ||UV semiconductor lasers:|| ||Prototype lasers emitting below 250nm are being developed for detection of chemical and biological agents using Raman excitation.|
| ||HVPE GaN templates:|| ||This program is aiming at developing freestanding GaN substrates or thick GaN templates on sapphire substrates. Such substrates are currently being used for the development of UV and blue-green LEDs for solid state lighting applications.|
| ||Nitrogen cluster source:|| ||A Gas cluster source has been incorporated in one of our MBE systems and is being used for the development of a variety of materials, such as AlN, GaN, and InN. These clusters are ionized and accelerated to voltages up to 30kV and used for growth as well as processing of materials.|
| ||A-plane growth of GaN:|| ||GaN grows along the A-direction when deposited onto R-plane sapphire. The polarization vector of the A-plane is in its plane rather than perpendicular to the plane. Thus, devices based on MQWs are not suffering from the QCSE.|
Pic of the moment
This is a picture of a fabricated mesa-LED from a fully processed wafer. The LED structure consists of a bottom n-layer, which is accessed by forming mesas via ICP etching of the top MQW-active region and p-layer. Shown in the picture are the metal ohmic contacts, TLM patterns for evaluation of contact properties, and alignment marks for photolithography.