Active III-V Devices - Photonic Crystal Lasers and Solar Cells
The Idea:
- To develop practical, low-threshold photonic crystal lasers and laser arrays for optical telecom, optical interconnects, and sensing applications.
- To investigate how modification of the optical density of states can affect performance of photovoltaic devices
Reasons:
- Photonic crystal cavities can modify the density of optical states enabling a large fraction of spontaneous emission to couple to a single lasing mode.
This coupled spontaneous emission allows photonic crystal lasers to have interesting properties for many applications including ultralow thresholds and ultrafast modulation rates.
- Coupled arrays of photonic crystal lasers can increase output powers to useful levels and still exhibit a significant Purcell effect.
- Low group velocity photonic crystal modes can be used to increase the absorption of sunlight in thin absorber layers, increasing the efficiency
and decreasing the cost of thin film solar cell technologies
- Photonic band gaps can be used to inhibit excess spontaneous emission in direct band gap solar cells, bringing efficiences closer to their
theoretical limits
Challenges:
- Develop surface passivation techniques to further reduce photonic crystal laser thresholds and reduce nonradiative recombination in
photonic crystal-based solar cells.
- Increase photonic crystal lsaer output powers to useful levels in structures that still exhibit significant Purcell effect.
- Develop fabrication techniques to allow electrical contacting of nanocavity structures.
- Develop photonic crystal structures that improve the absorption efficiency of thin film photovoltaic devices over the entire solar spectrum
Collaborators
- Tomas Sarmiento and Professor James Harris, Stanford University
- Marie Mayer and Prof. Eugene Haller, University of California Berkeley
- Bingyang Zhang and Prof. Yoshihisa Yamamoto, Stanford University
last modified on Thursday November 10, 2011