Time-resolved fluorescence up-conversion study of radiative recombination dynamics in III-nitride light emitting diodes over a wide bias range

You, Guofeng; Liu, Jie; Jiang, Zhenyu; Zhu, Yiming; Chen, Aping; Hu, Yong; Xiong, Fen; Henderson, Ron; Zhuang, Songlin; Xu, Jian

doi:10.1063/1.4819850

Cited by 3 publications

(4 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar change has been observed for photoluminescence decay time in a blue LED as function of bias voltage in an experiment with short pulse optical excitation. 25) There, a similar factor-of-three variation from about 14 ns at small forward bias of V bias = 2 V to 4 ns at V bias = −3 V was observed. The decrease in photoluminescence decay time coincided with an increasing photoluminescence intensity, in agreement with our interpretation of the influence of the built-in potential on carrier recombination.…”

Section: Resultssupporting

confidence: 54%

“…22) We suggested to use this effect to modify and possibly increase LED efficiency by a pulsed mode operation, where carrier injection and carrier recombination occur at different bias: carriers are injected into the QWs during a forward bias, and recombine during a reverse bias when the overlap of electron and hole wave functions are maximized. 23) While the general findings of the impact on bias were confirmed, [24][25][26] the approach did not yet result in a successful demonstration of droop reduction in LEDs. One reason is that state-of-the-art LEDs are optimized for efficiency at forward bias, such minimizing the effect of reverse bias on carrier recombination.…”

Section: Introductionmentioning

confidence: 97%

See 1 more Smart Citation

Spectral-temporal study on the output power of green InGaN LEDs

Simon

Wachs

Schwarz

2019

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

To mitigate the “green gap” effect in green light-emitting diodes (LEDs), we investigate a pulsed mode operation, where carrier injection and carrier recombination happen at different bias. Carriers are injected into the quantum wells during forward bias, and recombine during reverse bias when the overlap of electron and hole wave functions is maximized. For this, we investigate the spectral-temporal properties of commercial green LEDs during pulsed operation with varying forward current from 2,5 up to 70 mA and reverse bias from 0 to −3 V. At the falling edge of the electrical signal an increase of the intensity and blue-shift of the emission could be demonstrated, indicating the dynamic reduction of the quantum-confined stark effect. However, droop curves measured in pulsed mode did not show an absolute improvement in efficiency, compared to cw droop curves. We conclude that green LEDs have to be optimized for this mode of operation to show an absolute increase in efficiency in pulsed mode.

show abstract

Section: Resultssupporting

confidence: 54%

Section: Introductionmentioning

confidence: 97%

Spectral-temporal study on the output power of green InGaN LEDs

Simon

Wachs

Schwarz

2019

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…Charge carrier lifetime is commonly used as one of the parameters that describes material quality and determines the overall efficiency of devices [3][4][5]. The parameter is used in characterisation for various devices, such as photovoltaics (PV) [6], laser diodes [7], light-emitting diodes [8] and other semiconductor devices. One of the most established techniques for measuring charge carrier lifetimes is time-resolved photoluminescence (TRPL).…”

Section: Introductionmentioning

confidence: 99%

“…Acquiring spatially-resolved measurements reveals the variations in charge carrier lifetimes across the measured sample, which is useful in terms of understanding the quality of the material [8]. Having the spatial information helps understand the charge carrier diffusion within the material and identify recombination centres [6].…”

Section: Introductionmentioning

confidence: 99%

Development of time-resolved photoluminescence microscopy of semiconductor materials and devices using a compressed sensing approach

Baltušis,

Koutsourakis,

Wood

et al. 2023

Meas. Sci. Technol.

View full text Add to dashboard Cite

Charge carrier lifetime is a key property of semiconductor materials for photonic applications. One of the most established methods for measuring lifetimes is time-resolved photoluminescence (TRPL), which is typically performed as a single-point measurement. In this paper, we demonstrate a new time-correlated single photon counting method (TCSPC) for TRPL microscopy, for which spatial information can be achieved without requiring point-by-point scanning through the use of a compressed sensing approach. This enables image acquisition with a single pixel detector for mapping the lifetime of semiconductors with high repeatability. The methodology for signal acquisition and image reconstruction was developed and tested through simulations. Effects of noise levels on the reliability and quality of image reconstruction were investigated. Finally, the method was implemented experimentally to demonstrate a proof-of-concept compressed sensing TCSPC imaging system for acquiring TRPL maps of semiconductor materials and devices. TRPL imaging results of a semiconductor device acquired using a compressed sensing approach are presented and compared with results of TRPL mapping of the same excitation area measured through a point-by-point method. The feasibility of the methodology is demonstrated and the benefits and challenges of the experimental prototype system are presented and discussed.

show abstract

Photoluminescence Upconversion Spectroscopy

Chosrowjan¹,

Taniguchi²

2020

Digital Encyclopedia of Applied Physics

View full text Add to dashboard Cite

The basic physical concepts and main characteristics of transient photoluminescence upconversion spectroscopy, including requirements for nonlinear crystals, acceptance angle, quantum efficiency for upconversion, group velocity mismatch, and photometric calibration, are presented. The main aspects relevant to building an ultrafast upconversion spectrometer are emphasized. Single‐wavelength and broadband implementations of the technique, as well as photoluminescence upconversion microscope, have been presented and discussed. Application examples of the technique in different fields of physics, chemistry, and biology have been presented.

show abstract

Time-resolved fluorescence up-conversion study of radiative recombination dynamics in III-nitride light emitting diodes over a wide bias range

Cited by 3 publications

References 16 publications

Spectral-temporal study on the output power of green InGaN LEDs

Spectral-temporal study on the output power of green InGaN LEDs

Development of time-resolved photoluminescence microscopy of semiconductor materials and devices using a compressed sensing approach

Photoluminescence Upconversion Spectroscopy

Contact Info

Product

Resources

About