Fabrication of quantum dot array diffraction grating for soft x-ray spectroscopy

2007 ◽  
Author(s):  
Min Zhao ◽  
XiaoLi Zhu ◽  
Baoqin Chen ◽  
ChangQing Xie ◽  
Ming Liu ◽  
...  
2010 ◽  
Vol 81 (7) ◽  
pp. 073508 ◽  
Author(s):  
Longyu Kuang ◽  
Chuanke Wang ◽  
Zhebin Wang ◽  
Leifeng Cao ◽  
Xiaoli Zhu ◽  
...  

2016 ◽  
Vol 18 (6) ◽  
pp. 4300-4303 ◽  
Author(s):  
J. Huang ◽  
Y. Tang ◽  
K. L. Mulfort ◽  
X. Zhang

In this work, we investigated photoinduced charge separation dynamics in a CdSe quantum dot/cobaloxime molecular catalyst hybrid using the combination of transient optical (OTA) and X-ray absorption (XTA) spectroscopy.


1997 ◽  
Vol 306 (2) ◽  
pp. 198-204 ◽  
Author(s):  
A.A. Darhuber ◽  
J. Stangl ◽  
V. Holy ◽  
G. Bauer ◽  
A. Krost ◽  
...  

1998 ◽  
Vol 58 (12) ◽  
pp. 7934-7943 ◽  
Author(s):  
V. Holý ◽  
A. A. Darhuber ◽  
J. Stangl ◽  
S. Zerlauth ◽  
F. Schäffler ◽  
...  

2013 ◽  
Vol 42 (5) ◽  
pp. 809-814 ◽  
Author(s):  
Ayomide Atewologun ◽  
Wangyao Ge ◽  
Adrienne D. Stiff-Roberts

2021 ◽  
Vol 21 (7) ◽  
pp. 3800-3805
Author(s):  
Abdul Razzaq ◽  
Muhammad Zafar ◽  
Tahir Saif ◽  
Jun Young Lee ◽  
Jung Ki Park ◽  
...  

In this investigation we report the formation of thin ZnO recombination barrier layer at TiO2/CdS interface aimed for the improvement in performance of CdS sensitized solar cell. The film was deposited upon nanocrystalline mesoporous TiO2 surface by following a simple chemical process and characterized, using UV-Visible spectroscopy, X-ray diffraction and electron dispersive X-ray measurements. The insertion of ZnO thin layer enhances the QDSC (Quantum dot sensitized solar cell) performance, contributed mainly by an increase in open circuit voltage (Voc) due to reduced electron back transfer from TiO2 conduction band. Moreover, the analysis of photovoltaic characteristics upon increasing the thickness of the ZnO film reveals that the ZnO recombination barrier layer with optimum thickness at porous TiO2/CdS interface proved to be an effective potential barrier for minimizing electron back recombination.


2020 ◽  
Vol 10 (17) ◽  
pp. 6081
Author(s):  
Junekyun Park ◽  
Eunkyu Shin ◽  
Jongwoo Park ◽  
Yonghan Roh

We demonstrated the way to improve the characteristics of quantum dot light emitting diodes (QD-LEDs) by adding a simple step to the conventional fabrication process. For instance, we can effectively deactivate the surface defects of quantum dot (QD) (e.g., CdSe/ZnS core-shell QDs in the current work) with the SiO bonds by simply mixing QDs with hexamethyldisilazane (HMDS) under atmospheric conditions. We observed the substantial improvement of device characteristics such that the current efficiency, the maximum luminance, and the QD lifetime were improved by 1.7–1.8 times, 15–18%, and nine times, respectively, by employing this process. Based on the experimental data (e.g., energy dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS)), we estimated that the growth of the SiOx on the surface of QDs is self-limited: the SiOx are effective to passivate the surface defects of QDs without deteriorating the intrinsic properties including the color-purity of QDs. Second, we proposed that the emission profiling study can lead us to the fundamental understanding of charge flow in each layer of QD-LEDs. Interestingly enough, many problems related to the charge-imbalance phenomenon were simply solved by selecting the combination of thicknesses of the hole transport layer (HTL) and the electron transport layer (ETL).


2016 ◽  
Vol 12 ◽  
pp. 79-87 ◽  
Author(s):  
Soumya Ranjan Patra ◽  
B. Mallick ◽  
S.K. Samal ◽  
S.C. Mishra ◽  
P. Pattojoshi ◽  
...  

Semiconducting polymer based X-ray detector design is quite interesting and challenging task for the researchers. Because of low X-ray attenuation of polymers, the device becomes insensitive. In the paper we report a way through the introduction of fluorescent nanoparticles to increase the X-ray detection probability.The Mimosa pudica fibre was coated with CdSe-CdS quantum dot-in-rods on the surface by chemical dipping processes. The fibre morphology and microstructure have been analysed by TEM and SEM techniques. The well-oriented CdSe-CdS quantum dot-in-rods have been observed in TEM with an aspect ratio (rod length ̸ rod diameter) of 28.7×3.5 nm and quantum yield 78% of a sharp emission peak at 545 nm. The CdSe-CdS quantum dot-in-rods coated M. pudica fibre, as observed in SEM, possesses a honeycomb structure of the nano-material. It is expected that the interaction between static-electric field of the fibre and the field produced by the above quantum particle causes to form a well-ordered honeycomb cover on the fibre of the surface. The goal of this study is to confirm the feasibility of the X-ray imaging detection system based on the quantum size effect on coated conducting fibre.


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