Density of Surface States at CdSe Quantum Dots by Fitting of Temperature-Dependent Surface Photovoltage Transients with Random Walk Simulations

2013 ◽  
Vol 117 (12) ◽  
pp. 6462-6468 ◽  
Author(s):  
Steffen Fengler ◽  
Elisabeth Zillner ◽  
Thomas Dittrich
Keyword(s):  
Quantum Dots ◽  
Random Walk ◽  
Surface States ◽  
Surface Photovoltage ◽  
Cdse Quantum Dots ◽  
Temperature Dependent

Temperature-Dependent Photoluminescence in Coupling Structures of CdSe Quantum Dots and a ZnCdSe Quantum Well

2005 ◽  
Vol 22 (6) ◽  
pp. 1518-1521 ◽  
Author(s):  
Jin Hua ◽  
Zhang Li-Gong ◽  
Zheng Zhu-Hong ◽  
An Li-Nan ◽  
Lu You-Ming ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Quantum Well ◽  
Cdse Quantum Dots ◽  
Temperature Dependent ◽  
Temperature Dependent Photoluminescence

scholarly journals Gas Sensitivity of In0.3Ga0.7As Surface QDs Coupled to Multilayer Buried QDs

2020 ◽  
Vol 10 (3) ◽  
pp. 283-290
Author(s):  
Guodong Wang ◽  
Zengguang Liu ◽  
Junjun Wang ◽  
Yingli Yang ◽  
Xiaolian Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electrical Response ◽  
Strong Dependence ◽  
Surface States ◽  
Reference Structure ◽  
Temperature Dependent ◽  
Gas Sensitivity ◽  
Acetone Concentration ◽  
Pl Spectra ◽  
Coupling Structure

AbstractA detailed analysis of the electrical response of In0.3Ga0.7As surface quantum dots (SQDs) coupled to 5-layer buried quantum dots (BQDs) is carried out as a function of ethanol and acetone concentration while temperature-dependent photoluminescence (PL) spectra are also analyzed. The coupling structure is grown by solid source molecular beam epitaxy. Carrier transport from BQDs to SQDs is confirmed by the temperature-dependent PL spectra. The importance of the surface states for the sensing application is once more highlighted. The results show that not only the exposure to the target gas but also the illumination affect the electrical response of the coupling sample strongly. In the ethanol atmosphere and under the illumination, the sheet resistance of the coupling structure decays by 50% while it remains nearly constant for the reference structure with only the 5-layer BQDs but not the SQDs. The strong dependence of the electrical response on the gas concentration makes SQDs very suitable for the development of integrated micrometer-sized gas sensor devices.

Temperature dependent synthesis and optical properties of CdSe quantum dots

2012 ◽  
Vol 38 (7) ◽  
pp. 5575-5583 ◽  
Author(s):  
Wen Mi ◽  
Jintao Tian ◽  
Weiguo Tian ◽  
Jinhui Dai ◽  
Xin Wang ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Cdse Quantum Dots ◽  
Temperature Dependent

Temperature-dependent photovoltaic behavior of CdSe quantum dots/P3HT hybrid thinfilm

2013 ◽  
Vol 49 ◽  
pp. 1-4 ◽  
Author(s):  
Hui-chao Zhang ◽  
Xiao-wei Du ◽  
Yu-qiao Wang ◽  
Qiu-mei Guan ◽  
Yue-ming Sun ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cdse Quantum Dots ◽  
Temperature Dependent ◽  
Photovoltaic Behavior

scholarly journals Simulation of the luminescence spectrum of CdSe quantum dots

2013 ◽  
Vol 16 (4) ◽  
pp. 61-67
Author(s):  
Cuong Chi Huynh ◽  
Luan Nguyen Thanh Huynh ◽  
Vinh Quang Lam ◽  
Dat Thanh Huynh
Keyword(s):  
Quantum Dots ◽  
Room Temperature ◽  
Surface States ◽  
Thiol Group ◽  
Experimental Investigations ◽  
Cdse Quantum Dots ◽  
Nano Particle ◽  
Small Quantum ◽  
Organic Capping ◽  
Matlab Programming

CdSe quantum dots were prepared via a colloidal route using an organic capping agent consist thiol group (SH). We explicitly calculated the exciton binding energy and we incorporate the exciton contribution then combined it with quantum confinement model and surface states to see its effect on photoluminescence. The results obtained by using MATLAB programming. Calculations took place at room temperature on small quantum dots (1 - 5 nm). In conclusion, our results are quite new and it effect some of the feature that has quite close correspondence with the experimental. The results are also in conformity with other theoretical and experimental investigations. This study shows the applications of photoluminescence spectrum in determination the size of nano particle, distribution of size and surface energy level of CdSe quantum dots.

Effect of Cd0.5Zn0.5S shells on temperature-dependent luminescence kinetics of CdSe quantum dots

RSC Advances ◽  
2014 ◽  
Vol 4 (82) ◽  
pp. 43800-43805 ◽  
Author(s):  
Ping Yang ◽  
Hsueh-Shih Chen ◽  
Sha Zhang ◽  
Jie Zhao ◽  
Yingying Du ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Cdse Quantum Dots ◽  
Temperature Dependent ◽  
Luminescence Kinetics ◽  
Kinetics Of

Size and Temperature Dependent Phonon Spectra of Spherical CdSe Quantum Dots Prepared via a Refined Phosphonic Acid Assisted Organometallic Route

2011 ◽  
Author(s):  
Liangliang Chen ◽  
Yiwen Chen ◽  
Xiulin Ruan
Keyword(s):  
Quantum Dots ◽  
Temperature Dependence ◽  
Phosphonic Acid ◽  
Phonon Frequency ◽  
Negative Temperature ◽  
Cdse Quantum Dots ◽  
Narrow Size Distribution ◽  
Temperature Dependent ◽  
Visible Absorption ◽  
Phonon Spectra

Spherical CdSe quantum dots (QDs) with a narrow size distribution were synthesized using a refined phosphonic-acid-assisted organometallic route. Visible absorption spectra show that as reaction time increases the absorption peak will shift to longer wavelength. HRTEM image confirmed the high-crystallinity of the as-prepared QDs. Raman spectroscopy was used to investigate the size and temperature dependence of the phonon spectra. As temperature increases, the LO-phonon frequency will decrease and the bandwidth will increase. As size increases, the LO-phonon frequency will increase and the bandwidth will decrease. However, when the temperature is above 400 K, the LO-phonon frequency in the smaller dots is higher than that in the larger dots due to the weaker negative temperature dependence of the LO-phonon frequency in the smaller dots.

Temperature-Dependent Photoluminescence and Absoprtion of CdSe Quantum dots Embedded in PMMA

2008 ◽  
Vol 52 (5) ◽  
pp. 1510-1513 ◽  
Author(s):  
Tran Thi Kim Chi ◽  
Ung Thi Dieu Thuy ◽  
Nguyen Quang Liem ◽  
Man Hoai Nam ◽  
Do Xuan Thanh
Keyword(s):  
Quantum Dots ◽  
Cdse Quantum Dots ◽  
Temperature Dependent ◽  
Temperature Dependent Photoluminescence
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