Codoping n- and p-Type Impurities in Colloidal Silicon Nanocrystals: Controlling Luminescence Energy from below Bulk Band Gap to Visible Range

2013 ◽  
Vol 117 (22) ◽  
pp. 11850-11857 ◽  
Author(s):  
Hiroshi Sugimoto ◽  
Minoru Fujii ◽  
Kenji Imakita ◽  
Shinji Hayashi ◽  
Kensuke Akamatsu
2018 ◽  
Vol 9 (24) ◽  
pp. 5405-5414 ◽  
Author(s):  
Erica M. Chen ◽  
Logan Williams ◽  
Alan Olvera ◽  
Cheng Zhang ◽  
Mingfei Zhang ◽  
...  

We report the synthesis of CTSe, a p-type titanium copper selenide semiconductor. Its band gap (1.15 eV) and its ultra-large absorption coefficient (105 cm−1) in the entire visible range make it a promising Earth-abundant solar absorber material.


2021 ◽  
Vol 125 (13) ◽  
pp. 7495-7501
Author(s):  
Gang Wang ◽  
Jinju Zheng ◽  
Boyi Xu ◽  
Chaonan Zhang ◽  
Yue Zhu ◽  
...  

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 988
Author(s):  
Chrysa Aivalioti ◽  
Alexandros Papadakis ◽  
Emmanouil Manidakis ◽  
Maria Kayambaki ◽  
Maria Androulidaki ◽  
...  

Nickel oxide (NiO) is a p-type oxide and nitrogen is one of the dopants used for modifying its properties. Until now, nitrogen-doped NiO has shown inferior optical and electrical properties than those of pure NiO. In this work, we present nitrogen-doped NiO (NiO:N) thin films with enhanced properties compared to those of the undoped NiO thin film. The NiO:N films were grown at room temperature by sputtering using a plasma containing 50% Ar and 50% (O2 + N2) gases. The undoped NiO film was oxygen-rich, single-phase cubic NiO, having a transmittance of less than 20%. Upon doping with nitrogen, the films became more transparent (around 65%), had a wide direct band gap (up to 3.67 eV) and showed clear evidence of indirect band gap, 2.50–2.72 eV, depending on %(O2-N2) in plasma. The changes in the properties of the films such as structural disorder, energy band gap, Urbach states and resistivity were correlated with the incorporation of nitrogen in their structure. The optimum NiO:N film was used to form a diode with spin-coated, mesoporous on top of a compact, TiO2 film. The hybrid NiO:N/TiO2 heterojunction was transparent showing good output characteristics, as deduced using both I-V and Cheung’s methods, which were further improved upon thermal treatment. Transparent NiO:N films can be realized for all-oxide flexible optoelectronic devices.


2011 ◽  
Vol 5 (4) ◽  
pp. 153-155 ◽  
Author(s):  
Seiji Yamazoe ◽  
Shunsuke Yanagimoto ◽  
Takahiro Wada
Keyword(s):  
Band Gap ◽  

2009 ◽  
Vol 67 ◽  
pp. 191-196 ◽  
Author(s):  
Lubna Hashmi ◽  
M.S. Qureshi ◽  
R.N. Dubey ◽  
M.M. Malik ◽  
Ishrat Alim ◽  
...  

A broad range of II-VI materials has been investigated in order to produce light in the full visible range for optoelectronic applications. The present investigation was carried out for the spectroscopic analysis and synthesis of wide band gap cadmium sulfide nanoparticles. Large-band gap semiconductors have the added advantage in that; they can support higher electric field before breaking down, which means that they can be used for high-power electronic devices.Synthesis has been carried out using colloidal synthesis technique at low temperature. The size, stabilization and optical properties were studied using UV-vis Spectrophotometer and Spectroflourometer. Further, the structural studies of synthesized powder were carried out using X-ray diffraction technique; which also confirms the formation of desired product. The capping ligand and the impurities present in the sample were characterized by Fourier transform infra red spectroscopy. Synthesized CdS powder dispersed in aqueous media gave the value of 193 nm for the onset wavelength using UV-vis spectrophotometer, which is significantly blue-shifted compared to bulk CdS and shows the quantum confinement effect. From the onset wavelength the radius of CdS quantum dot calculated using the Brus equation was found to be ca. 0.7 nm.


2009 ◽  
Vol 95 (17) ◽  
pp. 172109 ◽  
Author(s):  
Anderson Janotti ◽  
Eric Snow ◽  
Chris G. Van de Walle

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
A. A. Faremi ◽  
S. S. Oluyamo ◽  
O. Olubosede ◽  
I. O. Olusola ◽  
M. A. Adekoya ◽  
...  

Abstract In this paper, energy band gaps and electrical conductivity based on aluminum selenide (Al2Se3) thin films are synthesized electrochemically using cathodic deposition technique, with graphite and carbon as cathode and anode, respectively. Synthesis is done at 353 K from an aqueous solution of analytical grade selenium dioxide (SeO2), and aluminum chloride (AlCl2·7H2O). Junctions-based Al2Se3 thin films from a controlled medium of pH 2.0 are deposited on fluorine-doped tin oxide (FTO) substrate using potential voltages varying from 1,000 mV to 1,400 mV and 3 minutes −15 minutes respectively. The films were characterized for optical properties and electrical conductivity using UV-vis and photoelectrochemical cells (PEC) spectroscopy. The PEC reveals a transition in the conduction of the films from p-type to n-type as the potential voltage varies. The energy band gap reduces from 3.2 eV to 2.9 eV with an increase in voltage and 3.3 eV to 2.7 eV with increase in time. These variations indicate successful fabrication of junction-based Al2Se3 thin films with noticeable transition in the conductivity type and energy band gap of the materials. Consequently, the fabricated Al2Se3 can find useful applications in optoelectronic devices.


2011 ◽  
Vol 20 (04) ◽  
pp. 787-799 ◽  
Author(s):  
ANJA HAASE ◽  
ELKE KRAKER ◽  
JOACHIM KRENN ◽  
CHRISTIAN PALFINGER ◽  
SABINE HEUSING ◽  
...  

We describe the fabrication and characterization of organic photodiodes on solution cast ITO (tin doped indium oxide) bottom electrodes. ITO coatings were produced by gravure printing process on PET and PEN substrates. The sheet resistance could be decreased by heat treatment at 120°C under forming gas atmosphere ( N 2/ H 2) to 1.5 kΩ. The transmission of the ITO coated PET and PEN substrates is more than 80% in the visible range. The printed films were hardened under UV-irradiation at low temperatures (< 130°C) and used as the bottom electrode of an organic photodiode (OPD), consisting of a stacked layer of copper phthalocyanine ( p -type material), perylene tetracarboxylic bisbenzimidazole ( n -type material) and Aluminium tris(8-hydroxyquinoline). The performance of the photodiodes with printed ITO on plastic substrates could be improved by adding a smoothing layer of PEDOT/PSS (Baytron® P) on the ITO coated films and was then similar to the performance of photodiodes with semi-transparent gold as anode. These results demonstrate the suitability of the printed ITO layers as bottom electrode for organic photodiodes. Furthermore the influence of different treatments (forming gas and oxygen plasma treatment) of the ITO bottom electrode on the current-voltage characteristics of the OPDs was studied.


2009 ◽  
Vol 94 (20) ◽  
pp. 202103 ◽  
Author(s):  
Min-Ling Liu ◽  
Fu-Qiang Huang ◽  
Li-Dong Chen ◽  
I-Wei Chen

ACS Nano ◽  
2013 ◽  
Vol 7 (6) ◽  
pp. 5017-5023 ◽  
Author(s):  
Paul J. Simmonds ◽  
Christopher D. Yerino ◽  
Meng Sun ◽  
Baolai Liang ◽  
Diana L. Huffaker ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document