Abstract

Understanding of light-emitting diode lamp behaviour is essential to support the use of these devices as illumination sources in near infrared spectroscopy. Spectral variation in light-emitting diode peak output (680, 700, 720, 735, 760, 780, 850, 880 and 940 nm) was assessed over time from power up and with variation in environmental temperature. Initial light-emitting diode power up to full intensity occurred within a measurement cycle (12 ms), then intensity decreased exponentially over approximately 6 min, a result ascribed to an increase in junction temperature as current is passed through the light-emitting diode. Some light-emitting diodes displayed start-up output characteristics on their first use, indicating the need for a short light-emitting diode ‘burn in’ period, which was less than 24 h in all cases. Increasing the ambient temperature produced a logarithmic decrease in overall intensity of the light-emitting diodes and a linear shift to longer wavelength of the peak emission. This behaviour is consistent with the observed decrease in the I_AD Index (absorbance difference between 670 nm and 720 nm, A₆₇₀–A₇₂₀) with increased ambient temperature, as measured by an instrument utilising light-emitting diode illumination (DA Meter). Instruments using light-emitting diodes should be designed to avoid or accommodate the effect of temperature. If accommodating temperature, as light-emitting diode manufacturer specifications are broad, characterisation is recommended.

© 2017 The Author(s)

Applicability of light-emitting diodes as light sources for active differential optical absorption spectroscopy measurements

Christoph Kern, Sebastian Trick, Bernhard Rippel, and Ulrich Platt
Appl. Opt. 45(9) 2077-2088 (2006)

Whiteness metric for light sources of arbitrary color temperatures: proposal and application to light-emitting-diodes.

Aurelien David, Michael R. Krames, and Kevin W. Houser
Opt. Express 21(14) 16702-16715 (2013)

Nitride light-emitting diodes for cryogenic temperatures

Mikolaj Chlipala, Henryk Turski, Marcin Siekacz, Katarzyna Pieniak, Krzesimir Nowakowski-Szkudlarek, Tadeusz Suski, and Czeslaw Skierbiszewski
Opt. Express 28(20) 30299-30308 (2020)

Light Emitting Diodes as an alternative ambient illumination source in photolithography environment

Dennis Corell, Haiyan Ou, Carsten Dam-Hansen, Paul-Michael Petersen, and Dan Friis
Opt. Express 17(20) 17293-17302 (2009)

Temperature dependent carrier localization in AlGaInN near-ultraviolet light-emitting diodes

Hongwei Wang, Yue Lin, Lihong Zhu, Yijun Lu, Yi Tu, Zhuguang Liu, Zhonghua Deng, Wenchao Tang, Yulin Gao, and Zhong Chen
Opt. Express 24(11) 11594-11600 (2016)