Local carrier dynamics around the sub-surface basal-plane stacking faults of GaN studied by spatio-time-resolved cathodoluminescence using a front-excitation-type photoelectron-gun

2013 ◽  
Vol 103 (5) ◽  
pp. 052108 ◽  
Author(s):  
K. Furusawa ◽  
Y. Ishikawa ◽  
M. Tashiro ◽  
K. Hazu ◽  
S. Nagao ◽  
...  
2010 ◽  
Vol 7 (7-8) ◽  
pp. 1894-1896 ◽  
Author(s):  
T. J. Badcock ◽  
S. Hammersley ◽  
M. J. Kappers ◽  
C. J. Humphreys ◽  
P. Dawson

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 708
Author(s):  
Daniele Catone ◽  
Giuseppe Ammirati ◽  
Patrick O’Keeffe ◽  
Faustino Martelli ◽  
Lorenzo Di Mario ◽  
...  

Ultrafast pump-probe spectroscopies have proved to be an important tool for the investigation of charge carriers dynamics in perovskite materials providing crucial information on the dynamics of the excited carriers, and fundamental in the development of new devices with tailored photovoltaic properties. Fast transient absorbance spectroscopy on mixed-cation hybrid lead halide perovskite samples was used to investigate how the dimensions and the morphology of the perovskite crystals embedded in the capping (large crystals) and mesoporous (small crystals) layers affect the hot-carrier dynamics in the first hundreds of femtoseconds as a function of the excitation energy. The comparative study between samples with perovskite deposited on substrates with and without the mesoporous layer has shown how the small crystals preserve the temperature of the carriers for a longer period after the excitation than the large crystals. This study showed how the high sensitivity of the time-resolved spectroscopies in discriminating the transient response due to the different morphology of the crystals embedded in the layers of the same sample can be applied in the general characterization of materials to be used in solar cell devices and large area modules, providing further and valuable information for the optimization and enhancement of stability and efficiency in the power conversion of new perovskite-based devices.


ACS Nano ◽  
2018 ◽  
Vol 12 (11) ◽  
pp. 11088-11097 ◽  
Author(s):  
Wooseok Yang ◽  
Seungmin Lee ◽  
Hyeok-Chan Kwon ◽  
Jeiwan Tan ◽  
Hyungsoo Lee ◽  
...  

2012 ◽  
Vol 717-720 ◽  
pp. 387-390 ◽  
Author(s):  
Robert E. Stahlbush ◽  
Qing Chun Jon Zhang ◽  
Anant K. Agarwal ◽  
Nadeemullah A. Mahadik

The effects of Shockley stacking faults (SSFs) that originate from half loop arrays (HLAs) on the forward voltage and reverse leakage were measured in 10 kV 4H-SiC PiN diodes. The presence of HLAs and basal plane dislocations in each diode in a wafer was determined by ultraviolet photoluminescence imaging of the wafer before device fabrication. The SSFs were expanded by electrical stressing under forward bias of 30 A/cm2, and contracted by annealing at 550 °C. The electrical stress increased both the forward voltage and reverse leakage. Annealing returned the forward voltage and reverse leakage to nearly their original behavior. The details of SSF expansion and contraction from a HLA and the effects on the electrical behavior of the PiN diodes are discussed.


2018 ◽  
Vol 924 ◽  
pp. 147-150
Author(s):  
Jörg Pezoldt ◽  
Andrei Alexandrovich Kalnin

A model based on the generation and recombination of defect was developed to describe the stability of stacking faults and basal plane dislocation loops in crystals with layered polytype structures. The stability of the defects configuration was analysed for stacking faults surrounded by Shockley and Frank partial dislocation as well as Shockley dislocation dipoles with long range elastic fields. This approach allows the qualitative prediction of defect subsystems in polytype structure in external fields.


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