Abstract
We present the fabrication, characterization, and demonstration of high-efficiency ultrasound-powered microlight emitting diodes (µLED) for use in optogenetic applications. InGaN based blue-emitting LED material wafers grown on a patterned sapphire substrate (PSS) were used to assist in the out-scattering of the light. The turn-on voltage of the LEDs is around 2.5 volts and the electrical ideality factor is 1.2 confirming high radiative recombination efficiency. A power density of more than 50 mW/mm 2 was obtained from a 130 × 300 µm 2 LED with a mesa of 100 µm diameter at 3 mA which is much more than is required to excite channelrhodopsin transfected neural cells. A high external quantum efficiency (EQE) of 33% is obtained at 3 mA measured in an integrating sphere. The peak wavelength of the µLED was measured at 483 nm at different current densities. The µLEDs are integrated directly onto a rectifier and Piezoelectric Transducer (PZT) harvester to realise a highly efficient ultrasound-powered light delivery unit capable to generate mWs of optical power. The concept was validated by powering the integrated device with ultrasound.
| Original language | English |
|---|---|
| Title of host publication | Integrated Photonics Platforms : Fundamental Research, Manufacturing and Applications |
| Editors | Roel G. Bates, Peter O'Brien, Laurent Vivien |
| Volume | 11364 |
| Publisher | SPIE - International Society for Optical Engineering |
| Publication date | 2020 |
| Article number | 113641I |
| ISBN (Electronic) | 9781510635005 |
| DOIs | |
| Publication status | Published - 2020 |
| Event | SPIE Photonics Europe - , France Duration: 6 Apr 2020 → 10 Apr 2020 |
Conference
| Conference | SPIE Photonics Europe |
|---|---|
| Country/Territory | France |
| Period | 06/04/2020 → 10/04/2020 |
Keywords
- Efficiency
- Implantable device
- Optogenetics
- PZT
- Rectifier
- Ultrasound powering
- µLED