Passivating Detrimental DX Centers in CH 3 NH 3 PbI 3 for Reducing Nonradiative Recombination and Elongating Carrier Lifetime

2019 ◽  
Vol 32 (6) ◽  
pp. 1906115 ◽  
Author(s):  
Jing Wang ◽  
Wei Li ◽  
Wan‐Jian Yin
Keyword(s):  
Carrier Lifetime ◽  
Nonradiative Recombination ◽  
Dx Centers

Carrier dynamics in spatially ordered InAs quantum dots

2002 ◽  
Vol 719 ◽  
Author(s):  
Jörg Siegert ◽  
Saulius Marcinkevièius ◽  
Andreas Gaarder ◽  
Rosa Leon ◽  
Sergio Chaparro ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Carrier Lifetime ◽  
Carrier Dynamics ◽  
Misfit Dislocations ◽  
Nonradiative Recombination ◽  
Photoluminescence Intensity ◽  
Inas Quantum Dots ◽  
Dislocation Arrays ◽  
Spatial Ordering

AbstractSpatial ordering of InAs quantum dots was attained by using misfit dislocations generated in a metastable InGaAs layer by means of thermal annealing. Influence of quantum dot positional ordering and dot proximity to dislocation arrays on carrier dynamics was studied by timeresolved photoluminescence. Substantially narrower inhomogeneous broadening from the ordered quantum dots was observed. Excitation intensity dependence of the photoluminescence intensity and carrier lifetime indicates stronger influence of nonradiative recombination for the ordered quantum dot structures. Numerical simulations allow estimating electron and hole capture rates from the quantum dots to traps located either at the quantum dot interfaces or in the vicinity of the quantum dots.

Optical Characterization of Defect-Related Carrier Recombination and Transport Features in GaN Substrates and CVD Diamonds

2008 ◽  
Vol 600-603 ◽  
pp. 1301-1304 ◽  
Author(s):  
Kęstutis Jarašiūnas ◽  
T. Malinauskas ◽  
R. Aleksiejunas ◽  
Bo Monemar ◽  
V. Ralchenko ◽  
...  
Keyword(s):  
Carrier Lifetime ◽  
Diffusion Length ◽  
Nonradiative Recombination ◽  
Carrier Generation ◽  
Picosecond Pulses ◽  
Photoelectrical Properties ◽  
Carrier Recombination ◽  
Favorable Conditions ◽  
Low Density Plasma

Defect related carrier recombination and transport properties have been investigated in differently doped HVPE GaN substrates and CVD diamond layers. Carrier generation by interband transitions or by deep-defect photoexcitation were realized for studies of GaN samples by using picosecond pulses at 351 nm or 527 nm. This allowed to create favorable conditions for radiative and nonradiative recombination in the crystals and reveal peculiarities of photoelectrical properties of high and low density plasma in undoped, doped, and compensated GaN. In CVD diamonds, carrier diffusion length was found equal to ~ 0.5 μm and non-dependent on nitrogen density, while the carrier lifetime varied from 0.2 to 0.6 ns.

Core Structures of Dislocations within CdTe Grains

2013 ◽  
Vol 1526 ◽  
Author(s):  
Chen Li ◽  
Timothy J. Pennycook ◽  
Donovan N. Leonard ◽  
Kim Jones ◽  
Zhiwei Wang ◽  
...  
Keyword(s):  
Partial Dislocation ◽  
High Efficiency ◽  
Carrier Lifetime ◽  
Minority Carrier ◽  
Minority Carrier Lifetime ◽  
Optical Absorption Coefficient ◽  
Nonradiative Recombination ◽  
Scanning Transmission ◽  
Direct Band ◽  
Z Contrast

ABSTRACTCdTe is well known as an excellent photovoltaic material for high efficiency solar cell applications because it has a direct band-gap, low fabrication cost and high optical absorption coefficient. However, the nonradiative recombination and low average minority carrier lifetime caused by the defects in CdTe solar cells limit its efficiency. So far, grain boundaries (GB) have been considered to be the major origin of the nonradiative recombination. However, we show that CdTe grains contain many dislocations that could limit device efficiency. Scanning transmission electron microscopy (STEM) was used to determine the atomic structure of intrinsic and extrinsic stacking faults and their terminating partial dislocation cores. Z-contrast images are sensitive to atomic number and are able to distinguish Cd and Te atomic columns. Unpaired Cd and Te atomic columns were found to form the partial dislocation cores, suggesting the presence of dangling bonds. These defects are likely to be electrically active, and may be the origin of the low minority carrier lifetime.

Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

1985 ◽  
Vol 43 ◽  
pp. 364-365
Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
Growth Conditions ◽  
Nonradiative Recombination ◽  
Device Structure ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

Low-Temperature Operation of Green, Blue and UV InGaN/GaN Multiple-Quantum-Well Light-Emitting Diodes

2003 ◽  
Vol 764 ◽  
Author(s):  
X. A. Cao ◽  
S. F. LeBoeuf ◽  
J. L. Garrett ◽  
A. Ebong ◽  
L. B. Rowland ◽  
...  
Keyword(s):  
Quantum Well ◽  
Light Emitting Diodes ◽  
Multiple Quantum Well ◽  
Light Output ◽  
Localized States ◽  
Multiple Quantum ◽  
Nonradiative Recombination ◽  
Light Emitting ◽  
Temperature Range ◽  
Green Leds

Absract:Temperature-dependent electroluminescence (EL) of InGaN/GaN multiple-quantum-well light-emitting diodes (LEDs) with peak emission energies ranging from 2.3 eV (green) to 3.3 eV (UV) has been studied over a wide temperature range (5-300 K). As the temperature is decreased from 300 K to 150 K, the EL intensity increases in all devices due to reduced nonradiative recombination and improved carrier confinement. However, LED operation at lower temperatures (150-5 K) is a strong function of In ratio in the active layer. For the green LEDs, emission intensity increases monotonically in the whole temperature range, while for the blue and UV LEDs, a remarkable decrease of the light output was observed, accompanied by a large redshift of the peak energy. The discrepancy can be attributed to various amounts of localization states caused by In composition fluctuation in the QW active regions. Based on a rate equation analysis, we find that the densities of the localized states in the green LEDs are more than two orders of magnitude higher than that in the UV LED. The large number of localized states in the green LEDs are crucial to maintain high-efficiency carrier capture at low temperatures.

Microwave transmission method for measuring minority-carrier lifetime in silicon slices

1971 ◽  
Vol 7 (25) ◽  
pp. 754
Author(s):  
R.E. Thomas ◽  
V. Makios ◽  
S. Ogletree ◽  
R. Mckillican
Keyword(s):  
Carrier Lifetime ◽  
Minority Carrier ◽  
Minority Carrier Lifetime ◽  
Transmission Method ◽  
Microwave Transmission

scholarly journals Marked enhancement of the photoresponsivity and minority-carrier lifetime of BaSi2 passivated with atomic hydrogen

2019 ◽  
Vol 3 (6) ◽  
Author(s):  
Zhihao Xu ◽  
Denis A. Shohonov ◽  
Andrew B. Filonov ◽  
Kazuhiro Gotoh ◽  
Tianguo Deng ◽  
...  
Keyword(s):  
Atomic Hydrogen ◽  
Carrier Lifetime ◽  
Minority Carrier ◽  
Minority Carrier Lifetime ◽  
Marked Enhancement

Carrier Lifetime of Au-Hyperdoped Ge using Terahertz Spectroscopy

2020 ◽  
Author(s):  
S. Senali Dissanayake ◽  
Naheed Ferdous ◽  
Hemi Gandhi ◽  
Eric Mazur ◽  
Elif Ertekin ◽  
...  
Keyword(s):  
Carrier Lifetime ◽  
Terahertz Spectroscopy

scholarly journals The Effect of Nitrogen Incorporation on the Optical Properties of Si-Rich a-SiCx Films Deposited by VHF PECVD

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 637
Author(s):  
Hongliang Li ◽  
Zewen Lin ◽  
Yanqing Guo ◽  
Jie Song ◽  
Rui Huang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Near Infrared ◽  
Chemical Vapor ◽  
Wide Bandgap ◽  
Nonradiative Recombination ◽  
Very High Frequency ◽  
N Content ◽  
High Frequency Plasma ◽  
Frequency Plasma ◽  
N Incorporation

The influence of N incorporation on the optical properties of Si-rich a-SiCx films deposited by very high-frequency plasma-enhanced chemical vapor deposition (VHF PECVD) was investigated. The increase in N content in the films was found to cause a remarkable enhancement in photoluminescence (PL). Relative to the sample without N incorporation, the sample incorporated with 33% N showed a 22-fold improvement in PL. As the N content increased, the PL band gradually blueshifted from the near-infrared to the blue region, and the optical bandgap increased from 2.3 eV to 5.0 eV. The enhancement of PL was suggested mainly from the effective passivation of N to the nonradiative recombination centers in the samples. Given the strong PL and wide bandgap of the N incorporated samples, they were used to further design an anti-counterfeiting label.

scholarly journals Numerical Investigation of Graphene as a Back Surface Field Layer on the Performance of Cadmium Telluride Solar Cell

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3275
Author(s):  
Devendra KC ◽  
Deb Kumar Shah ◽  
M. Shaheer Akhtar ◽  
Mira Park ◽  
Chong Yeal Kim ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Doping Concentration ◽  
Carrier Lifetime ◽  
Short Circuit ◽  
Back Surface ◽  
Back Surface Field ◽  
Cdte Solar Cell ◽  
Cdte Solar Cells ◽  
Surface Field

This paper numerically explores the possibility of ultrathin layering and high efficiency of graphene as a back surface field (BSF) based on a CdTe solar cell by Personal computer one-dimensional (PC1D) simulation. CdTe solar cells have been characterized and studied by varying the carrier lifetime, doping concentration, thickness, and bandgap of the graphene layer. With simulation results, the highest short-circuit current (Isc = 2.09 A), power conversion efficiency (h = 15%), and quantum efficiency (QE ~ 85%) were achieved at a carrier lifetime of 1 × 103 ms and a doping concentration of 1 × 1017 cm−3 of graphene as a BSF layer-based CdTe solar cell. The thickness of the graphene BSF layer (1 mm) was proven the ultrathin, optimal, and obtainable for the fabrication of high-performance CdTe solar cells, confirming the suitability of graphene material as a BSF. This simulation confirmed that a CdTe solar cell with the proposed graphene as the BSF layer might be highly efficient with optimized parameters for fabrication.

Sign in / Sign up

Export Citation Format

Share Document