Characterization of external quantum efficiency and absorption efficiency in GaAs/ InGaP double heterostructures for laser cooling applications

2010 ◽  
Author(s):  
Chengao Wang ◽  
Michael P. Hasselbeck ◽  
Chia-Yeh Li ◽  
Mansoor Sheik-Bahae
Keyword(s):  
Quantum Efficiency ◽  
Laser Cooling ◽  
External Quantum Efficiency ◽  
Absorption Efficiency ◽  
Double Heterostructures

Synthesis and Characterization of Novel Conjugated Light-Emitting Polymers

2002 ◽  
Vol 725 ◽  
Author(s):  
Michelle S. Liu ◽  
Xuezhong Jiang ◽  
Petra Herguth ◽  
Alex K.-Y. Jen
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Synthesis And Characterization ◽  
Hole Conductivity ◽  
Polymer Backbone ◽  
High Brightness ◽  
Light Emitting ◽  
Turn On

AbstractNovel fluorene-based conjugated light-emitting polymers have been designed and synthesized. By varying the compositions of the polymer backbone, the charge-injecting and -transporting properties of the polymers were significantly improved. The light-emitting diodes (LEDs) using these polymers as the emissive layers exhibited low turn-on voltage, a high external quantum efficiency, and high brightness due to balanced electron and hole conductivity.

Development of high quantum efficiency GaAs/GaInP double heterostructures for laser cooling

2013 ◽  
Vol 102 (25) ◽  
pp. 252102 ◽  
Author(s):  
Daniel A. Bender ◽  
Jeffrey G. Cederberg ◽  
Chengao Wang ◽  
Mansoor Sheik-Bahae
Keyword(s):  
Quantum Efficiency ◽  
Laser Cooling ◽  
High Quantum Efficiency ◽  
High Quantum ◽  
Double Heterostructures

Internal Mechanical Stresses and Conductivity Mechanisms of p-n-InAsPSb/InAs-Heterostructures

1997 ◽  
Vol 505 ◽  
Author(s):  
V. G. Sidorov ◽  
V. I. Sokolov ◽  
D. V. Sidorov
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Lattice Mismatch ◽  
Light Emitting Diode ◽  
Mechanical Stresses ◽  
Power Dependence ◽  
Tunnel Current ◽  
Light Emitting ◽  
Double Heterostructures

ABSTRACTInfluence of internal mechanical stresses (IMS) and dislocations on conductivity mechanisms and reliability of light emitting diode (LED) and laser InAsPSb/InAs double heterostructures has been investigated. It was shown that the presence of lattice mismatch of layers at p-n-heteroboundaries changes LED conductivity mechanisms the same way as longterm working challenges by current. It was determined that LED degradation has barrier character and is followed by appearance and growth of tunnel current components with power dependence of current from voltage. Reliability and external quantum efficiency decrease with growth of lattice mismatch.

Demonstration of ultra-small (0.2%) for mini-displays

2020 ◽  
Vol 14 (1) ◽  
pp. 011004
Author(s):  
Shubhra S. Pasayat ◽  
Chirag Gupta ◽  
Matthew S. Wong ◽  
Ryan Ley ◽  
Michael J. Gordon ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency

scholarly journals Phenylalkylammonium passivation enables perovskite light emitting diodes with record high-radiance operational lifetime: the chain length matters

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yuwei Guo ◽  
Sofia Apergi ◽  
Nan Li ◽  
Mengyu Chen ◽  
Chunyang Yin ◽  
...  
Keyword(s):  
Chain Length ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diodes ◽  
Surface Defects ◽  
Theoretical Modelling ◽  
Ion Migration ◽  
Light Emitting ◽  
Operational Lifetime ◽  
Chain Lengths

AbstractPerovskite light emitting diodes suffer from poor operational stability, exhibiting a rapid decay of external quantum efficiency within minutes to hours after turn-on. To address this issue, we explore surface treatment of perovskite films with phenylalkylammonium iodide molecules of varying alkyl chain lengths. Combining experimental characterization and theoretical modelling, we show that these molecules stabilize the perovskite through suppression of iodide ion migration. The stabilization effect is enhanced with increasing chain length due to the stronger binding of the molecules with the perovskite surface, as well as the increased steric hindrance to reconfiguration for accommodating ion migration. The passivation also reduces the surface defects, resulting in a high radiance and delayed roll-off of external quantum efficiency. Using the optimized passivation molecule, phenylpropylammonium iodide, we achieve devices with an efficiency of 17.5%, a radiance of 1282.8 W sr−1 m−2 and a record T50 half-lifetime of 130 h under 100 mA cm−2.

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