scholarly journals Several processes participating in a decrease and the droop of external quantum efficiency in green InGaN/GaN MQW structures

2021 ◽  
Vol 2086 (1) ◽  
pp. 012104
Author(s):  
N A Talnishnikh ◽  
E I Shabunina ◽  
N M Shmidt ◽  
A E Ivanov
Keyword(s):  
Grain Boundaries ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Charge Carriers ◽  
Experimental Results ◽  
Potential Fluctuations ◽  
Ingan Alloy

Abstract The obtained experimental results allow us to clarify the nature of mechanisms related to the presence of cations in disordered InGaN alloy and hetero-interfaces. The capture of charge carriers by cations reduces the external quantum efficiency (EQE) in green MQWs at j < 10 A/cm2. The EQE droop phenomenon caused by smoothed out lateral potential fluctuations occurs at j > 10 A/cm2. At j > 40 A/cm2 the droop associated with interactions between charge carriers and dislocations and grain boundaries takes place.

External quantum efficiency versus charge carriers mobility in polythiophene/methanofullerene based planar photodetectors

2007 ◽  
Vol 102 (2) ◽  
pp. 024503 ◽  
Author(s):  
M. Caironi ◽  
T. Agostinelli ◽  
D. Natali ◽  
M. Sampietro ◽  
R. Cugola ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Charge Carriers

scholarly journals Interfacial electrostatic interaction-enhanced photomultiplication for ultra-high external quantum efficiency of organic photodiodes

2021 ◽  
Author(s):  
Juhee Kim ◽  
Mingyun Kang ◽  
Sangjun Lee ◽  
Chan So ◽  
Dae Sung Chung
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Electrostatic Interactions ◽  
High Sensitivity ◽  
Image Sensor ◽  
Image Sensors ◽  
Charge Carriers ◽  
Gain Bandwidth ◽  
Electron States ◽  
Trapped Electron

Abstract A photomultiplication-type organic photodiode (PM-OPD), where an electric double layer (EDL) is strategically embedded, is demonstrated with an exceptionally high external quantum efficiency (EQE) of 2,210,000%, responsivity of 11,200 A W− 1, specific detectivity of 2.82 × 1014 Jones, and gain-bandwidth product of 1.92 × 107 Hz as well as high reproducibility. A metal-semiconductor Schottky interface consisting of an EDL enables the stabilization of trapped electron states within the acceptor domains of the photoactive layer by electrostatic interactions, boosting the PM-OPD gain generation. The effects of the EDL on the energetics of trapped electron states are confirmed by numerical simulations based on the drift-diffusion approximation of charge carriers. The feasibility of the fabricated high-EQE PM-OPD is demonstrated via a pixelated prototype image sensor. We believe that this new OPD platform opens up the possibility for the ultra-high-sensitivity organic image sensors, while maintaining the advantageous properties of organics.

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.

Simulation and modeling of the influence of temperature on CdS/CdTe thin film solar cell

2019 ◽  
Vol 87 (3) ◽  
pp. 30101 ◽  
Author(s):  
Abdel-baset H. Mekky
Keyword(s):  
Thin Film ◽  
Solar Cell ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Influence Of Temperature ◽  
Cdte Solar Cell ◽  
Cell Parameters ◽  
Current Voltage ◽  
Capacitance Voltage ◽  
Influence Of Temperature On

Semiconductor materials cadmium sulfide (CdS) and cadmium telluride (CdTe) are employed in the fabrication of thin film solar cells of relatively excessive power conversion efficiency and low producing price. Simulations of thin film CdS/CdTe solar cell were carried out using SCAPS-1D. The influence of temperature field on the variation of CdTe solar cell parameters such as current–voltage, capacitance–voltage characteristics and the external quantum efficiency was investigated theoretically. For use temperatures, one obtains the external quantum efficiency has the same profiles. However, the effect of the temperature on the Mott-Schottky curves is slightly noted by variations on the characteristics. This conclusion can be used by solar cell manufacturers to improve the solar cell parameters with the biggest possible gain in device performance.

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