Understanding and Engineering Valence Band Structures of III-Nitride Semiconductors forHigh-Efficiency Ultraviolet Lasers and Emitters
Abstract
Objective:The objective of this proposal is to advance the fundamental understanding of the physics of GaN-based active regions in nitride heterostructures in order to enable high-efficiency electrically-injected UV lasers and emitters with wavelengths ranging from 220 nm to 300 nm at room temperature.Approach:The fundamental physics of the valence band structure of conventional AlGaN quantum well (QW) active regions will be explained and transverse magnetic (TM) polarized lasing down to 220-230 nm will be demonstrated. To address the issue for transverse electric (TE) polarized laser from 240 - 300 nm, the solution will be based on the proposed novel AlGaN-delta-GaN QW structure. Other than AlGaN materials, an alternative solution by switching to the wide bandgap AlInN material system will be pursued, which was less studied in the field of UV lasers due to the growth challenges and unclear physics. The metal organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE) growths will be carried out with novel engineered AlInN QW, which will lead to 250 nm lasers. Finally, the novel ~top-down~ fabrication approach to potentially achieve large-area and uniform UV laser arrays with higher output power will be performed.Merit/Naval Relevance:DoD investments in nitride semiconductors have focused on high-power electronic applications, leaving LEDs to the commercial sector. UV lasers represent a third area, and one in which DoD investment is justified for potential applications including chemical and biological identification, decontamination, and real-time medical diagnostics. There is an ongoing DARPA program (LUSTER) on this topic, and opportunities for research at the 6.1/university level. Prof. Zhang has demonstrated a wide range of expertise and interest in areas ranging from solid-state physics to optical and electrical engineering to manufacturing. She has made significant contributions to topics including MOCVD growth, physics and device modeling, experimental measurements of properties including spontaneous emission rates, optical gain, and thermoelectric coefficients, and device fabrication. This innovative proposal builds on her expertise and will advance fundamental science with strong potential payoffs for DoD applications. The basic research and potential applications are relevant to the ONR Electromagnetic Materials Program and at least three ONR focus areas: 1) Assure Access to the Maritime Battlespace, 2) Autonomy & Unmanned Systems, and 3) Electromagnetic Maneuver Warfare.SOW:Year 1:Fully develop physics of optimized conventional AlGaN laser structureDemonstrate transverse-magnetic (TM) lasing based on conventional AlGaN quantum wells (QWs) Realize optimized AlGaN-delta-GaN QW laser structurePerform MOCVD or MBE growth with the optimized structure and demonstrate transverse-electric (TE) gain in 240 ~ 300 nm regionYear 2:Fully develop physics of AlInN QW active region and perform comprehensive study on the AlInN-delta-GaN QWTE-polarized lasing at room temperature from AlInN-delta-GaN QW active region with mid-UV wavelengthYear 3: ~Top down~ fabrication of nanowire/ nanopillar arrays for UV lasers based on selected approach
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141612524
Entities
People
- Jing Zhang
Organizations
- Office of Naval Research
- Rochester Institute of Technology
- United States Navy