@inproceedings{7f824d1071934c019d74e13bc0e27dcd,
title = "Realization of high efficiency ultrasound-powered micro-LEDs for optogenetics",
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/mm2 was obtained from a 130 × 300 µm2 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.",
keywords = "Efficiency, Implantable device, Optogenetics, PZT, Rectifier, Ultrasound powering, µLED",
author = "Tanmay Mondal and Kjeld Laursen and Seyedsina Hosseini and Amin Rashidi and Farshad Moradi and Brian Corbett",
note = "Publisher Copyright: {\textcopyright} 2020 SPIE; Integrated Photonics Platforms 2020: Fundamental Research, Manufacturing and Applications ; Conference date: 06-04-2020 Through 10-04-2020",
year = "2020",
doi = "10.1117/12.2555762",
language = "English",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Baets, \{Roel G.\} and Peter O'Brien and Laurent Vivien",
booktitle = "Integrated Photonics Platforms",
address = "United States",
}