scholarly journals Multiple Exciton Generation in Isolated and Interacting Silicon Nanocrystals

Nanoscale ◽  
2021 ◽  
Author(s):  
Ivan Marri ◽  
Stefano Ossicini
Keyword(s):  
Renewable Energy ◽  
Solar Cell ◽  
Silicon Nanocrystals ◽  
Photovoltaic Systems ◽  
Multiple Exciton Generation ◽  
Important Challenge ◽  
Low Dimensional ◽  
Low Dimensional Materials

An important challenge in the field of renewable energy is the development of novel nanostructured solar cell devices which implement low-dimensional materials to overcome the limits of traditional photovoltaic systems....

scholarly journals Effect of Confinement Strength on the Conversion Efficiency of Strained Core-Shell Quantum Dot Solar Cell-=SUP=-*-=/SUP=-

2020 ◽  
Vol 128 (10) ◽  
pp. 1534
Author(s):  
Anupam Sahu ◽  
Dharmendra Kumar
Keyword(s):  
Solar Cell ◽  
Quantum Dot ◽  
Conversion Efficiency ◽  
Cell Structure ◽  
Detailed Balance ◽  
Balance Model ◽  
Core Shell ◽  
Dimensional System ◽  
Multiple Exciton Generation ◽  
Low Dimensional

In this paper, the conversion efficiency (CE) of core-shell quantum dot (CSQD) solar cell is investigated within weak and strong confinements strength, using detailed balance model. The weak and strong confinement strength in solar cell structure is modeled using ZnTe/ZnSe and PbS/CdS CSQD, respectively. Considering size-dependent strain results of CE of CSQD solar cell for varying core radius is plotted with and without considering multiple exciton generation (MEG), and the results show the improvement in CE with MEG, thus indicating its importance in the low-dimensional system. The numerical results demonstrate that for the same CSQD size, the solar cell with a stronger confinement strength achieves the higher CE in comparison to the weaker confinement. Also, the MEG significantly increases the CE of stronger confined CSQD solar cell. The results plotted are in good agreement with the literature. Keywords: conversion efficiency, quantum dot, core-shell, solar cell, multiple exciton generation.

scholarly journals Women in the Singlet Fission World: Pearls in a Semi-Open Shell

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2922
Author(s):  
Joanna Stoycheva ◽  
Julia Romanova ◽  
Alia Tadjer
Keyword(s):  
Solar Cell ◽  
Focal Point ◽  
Open Shell ◽  
Generation Process ◽  
Singlet Fission ◽  
Software Developers ◽  
Multiple Exciton Generation ◽  
Cell Technologies ◽  
The Subject

Singlet fission, a multiple exciton generation process, can revolutionize existing solar cell technologies. Offering the possibility to double photocurrent, the process has become a focal point for physicists, chemists, software developers, and engineers. The following review is dedicated to the female investigators, predominantly theorists, who have contributed to the field of singlet fission. We highlight their most significant advances in the subject, from deciphering the mechanism of the process to designing coveted singlet fission materials.

scholarly journals The Highly Uniform Photoresponsivity from Visible to Near IR Light in Sb2Te3 Flakes

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1535
Author(s):  
Shiu-Ming Huang ◽  
Jai-Lung Hung ◽  
Mitch Chou ◽  
Chi-Yang Chen ◽  
Fang-Chen Liu ◽  
...  
Keyword(s):  
Band Structure ◽  
Energy Difference ◽  
Experimental Result ◽  
Light Illumination ◽  
Near Ir ◽  
State Band ◽  
Valence Bands ◽  
Low Dimensional ◽  
Low Dimensional Materials ◽  
Ir Light

Broadband photosensors have been widely studied in various kinds of materials. Experimental results have revealed strong wavelength-dependent photoresponses in all previous reports. This limits the potential application of broadband photosensors. Therefore, finding a wavelength-insensitive photosensor is imperative in this application. Photocurrent measurements were performed in Sb2Te3 flakes at various wavelengths ranging from visible to near IR light. The measured photocurrent change was insensitive to wavelengths from 300 to 1000 nm. The observed wavelength response deviation was lower than that in all previous reports. Our results show that the corresponding energies of these photocurrent peaks are consistent with the energy difference of the density of state peaks between conduction and valence bands. This suggests that the observed photocurrent originates from these band structure peak transitions under light illumination. Contrary to the most common explanation that observed broadband photocurrent carrier is mainly from the surface state in low-dimensional materials, our experimental result suggests that bulk state band structure is the main source of the observed photocurrent and dominates the broadband photocurrent.

scholarly journals Definition of a scoring parameter to identify low-dimensional materials components

2019 ◽  
Vol 3 (3) ◽  
Author(s):  
Peter Mahler Larsen ◽  
Mohnish Pandey ◽  
Mikkel Strange ◽  
Karsten Wedel Jacobsen
Keyword(s):  
Definition Of ◽  
Low Dimensional ◽  
Low Dimensional Materials

Reasonably designed 2D WS2 and CdS microwire heterojunction for high performance photoresponse

Nanoscale ◽  
2021 ◽  
Author(s):  
Z.Q. Zheng ◽  
Yuchen Zhou ◽  
Wei Gao ◽  
Li Zhang ◽  
Mengmeng Yang ◽  
...  
Keyword(s):  
High Performance ◽  
Low Dimensional ◽  
Low Dimensional Materials

Heterojunctions based on low-dimensional materials can combine the superiorities of each composition and realize novel properties. Herein, a mixed-dimensional heterojunction comprising multilayer WS2, CdS microwire and few-layer WS2 has been...

Bandgap Engineering of Silicon Quantum Dot Nanostructures for High Efficient Silicon Solar Cell: The Tandem Approach

2008 ◽  
Vol 1121 ◽  
Author(s):  
B. Rezgui ◽  
A. Sibai ◽  
T. Nychyporuk ◽  
O. Marty ◽  
M. Lemiti ◽  
...  
Keyword(s):  
Solar Cell ◽  
Silicon Nitride ◽  
Quantum Dot ◽  
Energy Range ◽  
Silicon Nanocrystals ◽  
Light Transmittance ◽  
Silicon Nitride Film ◽  
Third Generation ◽  
Solar Cell Application ◽  
High Efficient

AbstractA tandem approach is proposed using Silicon nanostructures to increase the efficiency of so-called third generation photovoltaic solar cells.Si quantum dot nanostructures (or silicon nanocrystals)are synthesized by depositing silicon-rich nitride (SRN) layers using plasma-enhanced chemical vapour deposition (PECVD). We have shown the intrinsic formation of silicon nanocrystals (nc-Si) in non-stoechiometric amorphous hydrogenated silicon nitride (a-SiNx:H) layers using pure silane (SiH4) and ammonia (NH3) as reactants. The NH3 would provide more hydrogen in the silicon nitride film leading to an improvement of the crystallinity of Si quantum dots (QD) by favouring the disorder-to-order transition. Furthermore, hydrogen dissociated from the NH3 would passivate the surface of a Si QD more effectively.Transmission Electron Microscopy (TEM) was employed to explore the microstructure of the as-deposited Si-in-SiNx composite films. The chemical bonds of these films were examined by using Fourier Transform Infrared (FTIR) spectroscopy in the wavenumber range from 400 to 4000 cm-1 with a resolution of 4 cm-1. The photoluminescence (PL) property of silicon nanocrystals in silicon-rich nitride (SRN) layers are also investigated. The peak position of PL could be controlled by adjusting the flow rates of ammonia and silane . Two types of luminescent mechanisms, such as radiative defects in the film and the quantum confinement effect (QCE) in silicon nanocrystals, have been proposed to explain the origin of light emission from these structures. These two mechanisms are inherently coexisting in our samples and the photoluminescence spectrum depends on the contribution of each other. The optical absorption properties of the deposited films are obtained and analyzed from light transmittance measurements. Spectroscopique ellipsometry have been performed in order to analyse the refractive index and the extension coefficient. All these measurements were carried out at room temperature. These techniques have given good correlation in the extraction of the absorption coefficient induced by the Si nanocrystal in the visible /UV energy range. Measurements of photocurrent have shown a great increase of the induced currrent in the visible/UV energy range for an optimum of deposition conditions. These results will be discussed in order to reach a better knowledge of the physical properties of this third generation photovoltaic all silicon included material for the tandem solar cell application approach.

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