Colour management of InGaN/GaN based monolithic two-wavelength LEDs

A. Yadav, M. Zulonas, I.E. Titkov, V.L. Zerova, K.A. Fedorova, A.F. Tsatsulnikov, W.V. Lundin, A.V. Sakharov, Grigorii S. Sokolovskii, E.U. Rafailov

Research output: Contribution to conferenceAbstract

Abstract

The recent advancement in the growth technology of InGaN/GaN has decently positioned InGaN based white LEDs to leap into the area of general or daily lighting. Monolithic white LEDs with multiple QWs were previously demonstrated by Damilano et al. [1] in 2001. However, there are several challenges yet to be overcome for InGaN based monolithic white LEDs to establish themselves as an alternative to other day-to-day lighting sources [2,3]. Alongside the key characteristics of luminous efficacy and EQE, colour rendering index (CRI) and correlated colour temperature (CCT) are important characteristics for these structures [2,4].
Investigated monolithic white structures were similar to that described in [5] and contained blue and green InGaN multiple QWs without short-period superlattice between them and emitting at 440 nm and 530 nm, respectively. The electroluminescence (EL) measurements were done in the CW and pulse current modes. An integration sphere (Labsphere “CDS 600” spectrometer) and a pulse generator (Agilent 8114A) were used to perform the measurements.
The CCT and Green/Blue radiant flux ratio were investigated at extended operation currents from 100mA to 2A using current pulses from 100ns to 100μs with a duty cycle varying from 1% to 95%. The strong dependence of the CCT on the duty cycle value, with the CCT value decreasing by more than three times at high duty cycle values (shown at the 300 mA pulse operation current) was demonstrated (Fig. 1). The pulse width variation seems to have a negligible effect on the CCT (Fig. 1). To account for the joule heating, a duty cycle more than 1% was considered as an overheated mode. For the 1% duty cycle it was demonstrated that the CCT was tuneable in three times by modulating input current and pulse width (Fig. 2). It has also been demonstrated that there is a possibility of keeping luminous flux independent of pulse width variation for a constant value of current pulse (Fig. 3).
Original languageEnglish
Publication statusPublished - 2014
Event28th Semiconductor and Integrated OptoElectronics conference - Cardiff, United Kingdom
Duration: 29 Apr 20141 May 2014

Conference

Conference28th Semiconductor and Integrated OptoElectronics conference
Abbreviated titleSIOE 2014
CountryUnited Kingdom
CityCardiff
Period29/04/141/05/14

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light emitting diodes
color
wavelengths
cycles
pulse duration
pulses
illuminating
temperature
pulse generators
Joule heating
electroluminescence
spectrometers

Cite this

Yadav, A., Zulonas, M., Titkov, I. E., Zerova, V. L., Fedorova, K. A., Tsatsulnikov, A. F., ... Rafailov, E. U. (2014). Colour management of InGaN/GaN based monolithic two-wavelength LEDs. Abstract from 28th Semiconductor and Integrated OptoElectronics conference, Cardiff, United Kingdom.
Yadav, A. ; Zulonas, M. ; Titkov, I.E. ; Zerova, V.L. ; Fedorova, K.A. ; Tsatsulnikov, A.F. ; Lundin, W.V. ; Sakharov, A.V. ; Sokolovskii, Grigorii S. ; Rafailov, E.U. / Colour management of InGaN/GaN based monolithic two-wavelength LEDs. Abstract from 28th Semiconductor and Integrated OptoElectronics conference, Cardiff, United Kingdom.
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title = "Colour management of InGaN/GaN based monolithic two-wavelength LEDs",
abstract = "The recent advancement in the growth technology of InGaN/GaN has decently positioned InGaN based white LEDs to leap into the area of general or daily lighting. Monolithic white LEDs with multiple QWs were previously demonstrated by Damilano et al. [1] in 2001. However, there are several challenges yet to be overcome for InGaN based monolithic white LEDs to establish themselves as an alternative to other day-to-day lighting sources [2,3]. Alongside the key characteristics of luminous efficacy and EQE, colour rendering index (CRI) and correlated colour temperature (CCT) are important characteristics for these structures [2,4].Investigated monolithic white structures were similar to that described in [5] and contained blue and green InGaN multiple QWs without short-period superlattice between them and emitting at 440 nm and 530 nm, respectively. The electroluminescence (EL) measurements were done in the CW and pulse current modes. An integration sphere (Labsphere “CDS 600” spectrometer) and a pulse generator (Agilent 8114A) were used to perform the measurements.The CCT and Green/Blue radiant flux ratio were investigated at extended operation currents from 100mA to 2A using current pulses from 100ns to 100μs with a duty cycle varying from 1{\%} to 95{\%}. The strong dependence of the CCT on the duty cycle value, with the CCT value decreasing by more than three times at high duty cycle values (shown at the 300 mA pulse operation current) was demonstrated (Fig. 1). The pulse width variation seems to have a negligible effect on the CCT (Fig. 1). To account for the joule heating, a duty cycle more than 1{\%} was considered as an overheated mode. For the 1{\%} duty cycle it was demonstrated that the CCT was tuneable in three times by modulating input current and pulse width (Fig. 2). It has also been demonstrated that there is a possibility of keeping luminous flux independent of pulse width variation for a constant value of current pulse (Fig. 3).",
author = "A. Yadav and M. Zulonas and I.E. Titkov and V.L. Zerova and K.A. Fedorova and A.F. Tsatsulnikov and W.V. Lundin and A.V. Sakharov and Sokolovskii, {Grigorii S.} and E.U. Rafailov",
year = "2014",
language = "English",
note = "28th Semiconductor and Integrated OptoElectronics conference, SIOE 2014 ; Conference date: 29-04-2014 Through 01-05-2014",

}

Yadav, A, Zulonas, M, Titkov, IE, Zerova, VL, Fedorova, KA, Tsatsulnikov, AF, Lundin, WV, Sakharov, AV, Sokolovskii, GS & Rafailov, EU 2014, 'Colour management of InGaN/GaN based monolithic two-wavelength LEDs' 28th Semiconductor and Integrated OptoElectronics conference, Cardiff, United Kingdom, 29/04/14 - 1/05/14, .

Colour management of InGaN/GaN based monolithic two-wavelength LEDs. / Yadav, A.; Zulonas, M.; Titkov, I.E.; Zerova, V.L.; Fedorova, K.A.; Tsatsulnikov, A.F.; Lundin, W.V.; Sakharov, A.V.; Sokolovskii, Grigorii S.; Rafailov, E.U.

2014. Abstract from 28th Semiconductor and Integrated OptoElectronics conference, Cardiff, United Kingdom.

Research output: Contribution to conferenceAbstract

TY - CONF

T1 - Colour management of InGaN/GaN based monolithic two-wavelength LEDs

AU - Yadav, A.

AU - Zulonas, M.

AU - Titkov, I.E.

AU - Zerova, V.L.

AU - Fedorova, K.A.

AU - Tsatsulnikov, A.F.

AU - Lundin, W.V.

AU - Sakharov, A.V.

AU - Sokolovskii, Grigorii S.

AU - Rafailov, E.U.

PY - 2014

Y1 - 2014

N2 - The recent advancement in the growth technology of InGaN/GaN has decently positioned InGaN based white LEDs to leap into the area of general or daily lighting. Monolithic white LEDs with multiple QWs were previously demonstrated by Damilano et al. [1] in 2001. However, there are several challenges yet to be overcome for InGaN based monolithic white LEDs to establish themselves as an alternative to other day-to-day lighting sources [2,3]. Alongside the key characteristics of luminous efficacy and EQE, colour rendering index (CRI) and correlated colour temperature (CCT) are important characteristics for these structures [2,4].Investigated monolithic white structures were similar to that described in [5] and contained blue and green InGaN multiple QWs without short-period superlattice between them and emitting at 440 nm and 530 nm, respectively. The electroluminescence (EL) measurements were done in the CW and pulse current modes. An integration sphere (Labsphere “CDS 600” spectrometer) and a pulse generator (Agilent 8114A) were used to perform the measurements.The CCT and Green/Blue radiant flux ratio were investigated at extended operation currents from 100mA to 2A using current pulses from 100ns to 100μs with a duty cycle varying from 1% to 95%. The strong dependence of the CCT on the duty cycle value, with the CCT value decreasing by more than three times at high duty cycle values (shown at the 300 mA pulse operation current) was demonstrated (Fig. 1). The pulse width variation seems to have a negligible effect on the CCT (Fig. 1). To account for the joule heating, a duty cycle more than 1% was considered as an overheated mode. For the 1% duty cycle it was demonstrated that the CCT was tuneable in three times by modulating input current and pulse width (Fig. 2). It has also been demonstrated that there is a possibility of keeping luminous flux independent of pulse width variation for a constant value of current pulse (Fig. 3).

AB - The recent advancement in the growth technology of InGaN/GaN has decently positioned InGaN based white LEDs to leap into the area of general or daily lighting. Monolithic white LEDs with multiple QWs were previously demonstrated by Damilano et al. [1] in 2001. However, there are several challenges yet to be overcome for InGaN based monolithic white LEDs to establish themselves as an alternative to other day-to-day lighting sources [2,3]. Alongside the key characteristics of luminous efficacy and EQE, colour rendering index (CRI) and correlated colour temperature (CCT) are important characteristics for these structures [2,4].Investigated monolithic white structures were similar to that described in [5] and contained blue and green InGaN multiple QWs without short-period superlattice between them and emitting at 440 nm and 530 nm, respectively. The electroluminescence (EL) measurements were done in the CW and pulse current modes. An integration sphere (Labsphere “CDS 600” spectrometer) and a pulse generator (Agilent 8114A) were used to perform the measurements.The CCT and Green/Blue radiant flux ratio were investigated at extended operation currents from 100mA to 2A using current pulses from 100ns to 100μs with a duty cycle varying from 1% to 95%. The strong dependence of the CCT on the duty cycle value, with the CCT value decreasing by more than three times at high duty cycle values (shown at the 300 mA pulse operation current) was demonstrated (Fig. 1). The pulse width variation seems to have a negligible effect on the CCT (Fig. 1). To account for the joule heating, a duty cycle more than 1% was considered as an overheated mode. For the 1% duty cycle it was demonstrated that the CCT was tuneable in three times by modulating input current and pulse width (Fig. 2). It has also been demonstrated that there is a possibility of keeping luminous flux independent of pulse width variation for a constant value of current pulse (Fig. 3).

M3 - Abstract

ER -

Yadav A, Zulonas M, Titkov IE, Zerova VL, Fedorova KA, Tsatsulnikov AF et al. Colour management of InGaN/GaN based monolithic two-wavelength LEDs. 2014. Abstract from 28th Semiconductor and Integrated OptoElectronics conference, Cardiff, United Kingdom.