Molecular doping of ZnO by ammonia: a possible shallow acceptor

2015 ◽  
Vol 3 (2) ◽  
pp. 339-344 ◽  
Author(s):  
Junhyeok Bang ◽  
Yi-Yang Sun ◽  
Damien West ◽  
Bruno K. Meyer ◽  
Shengbai Zhang

Ammonia can assume a Zn site in ZnO forming an isovalent substitutional defect, which can become an acceptor by capturing an interstitial H atom.

Author(s):  
Yu Jie Zheng ◽  
Qi Zhang ◽  
Omololu Odunmbaku ◽  
Zeping Ou ◽  
Meng Li ◽  
...  

Abstract Utilizing first-principles calculations, charge transfer doping process of single layer tin selenide (SL-SnSe) via the surface adsorption of various organic molecules was investigated. Effective p-type SnSe, with carrier concentration exceeding 3.59×1013 cm-2, was obtained upon adsorption of tetracyanoquinodimethane (TCNQ) or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F4TCNQ) on SL-SnSe due to their lowest unoccupied molecular orbital (LUMO) acting as shallow acceptor states. While we could not obtain effective n-type SnSe through adsorption of tetrathiafulvalene (TTF) or 1,4,5,8-tetrathianaphthalene (TTN) on pristine SnSe due to their highest occupied molecular orbitals (HOMO) being far from the conduction band edge of SnSe, this disadvantageous situation can be amended by the introduction of an external electric field perpendicular to the monolayer surface. It is found that Snvac will facilitate charge transfer from TTF to SnSe through introducing an unoccupied gap state just above the HOMO of TTF, thereby partially compensating for the p-type doping effect of Snvac. Our results show that both effective p-type and n-type SnSe can be obtained and tuned by charge transfer doping, which is necessary to promote its applications in nanoelectronics, thermoelectrics and optoelectronics.


2005 ◽  
Vol 108-109 ◽  
pp. 181-186 ◽  
Author(s):  
Valentin V. Emtsev ◽  
Boris A. Andreev ◽  
Gagik A. Oganesyan ◽  
D.I. Kryzhkov ◽  
Andrzej Misiuk ◽  
...  

Effects of compressive stress on oxygen agglomeration processes in Czochralski grown silicon heat treated at T= 450OC, used as a reference temperature, and T= 600OC to 800OC are investigated in some detail. Compressive stresses of about P= 1 GPa lead to enhanced formation of Thermal Double Donors in materials annealed over a temperature range of T= 450OC – 600OC. It has been shown that the formation of thermal donors at T= 450OC under normal conditions and compressive stress is accompanied with loss of substitutional boron. In contrast, the concentration of the shallow acceptor states of substitutional boron in silicon annealed under stress at T≥ 600OC remains constant. An enhancement effect of thermal donor formation is gradually weakened at T≥ 700OC. The oxygen diffusivity sensitive to mechanical stress is believed to be responsible for the observed effects in heat-treated silicon.


APL Materials ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 051101
Author(s):  
P. Storm ◽  
S. Gierth ◽  
S. Selle ◽  
M. S. Bar ◽  
H. von Wenckstern ◽  
...  
Keyword(s):  

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1899
Author(s):  
Mattia Pizzone ◽  
Maria Grazia Grimaldi ◽  
Antonino La La Magna ◽  
Neda Rahmani ◽  
Silvia Scalese ◽  
...  

Molecular Doping (MD) involves the deposition of molecules, containing the dopant atoms and dissolved in liquid solutions, over the surface of a semiconductor before the drive-in step. The control on the characteristics of the final doped samples resides on the in-depth study of the molecule behaviour once deposited. It is already known that the molecules form a self-assembled monolayer over the surface of the sample, but little is known about the role and behaviour of possible multiple layers that could be deposited on it after extended deposition times. In this work, we investigate the molecular surface coverage over time of diethyl-propyl phosphonate on silicon, by employing high-resolution morphological and electrical characterization, and examine the effects of the post-deposition surface treatments on it. We present these data together with density functional theory simulations of the molecules–substrate system and electrical measurements of the doped samples. The results allow us to recognise a difference in the bonding types involved in the formation of the molecular layers and how these influence the final doping profile of the samples. This will improve the control on the electrical properties of MD-based devices, allowing for a finer tuning of their performance.


1999 ◽  
Vol 595 ◽  
Author(s):  
Giancarlo Salviati ◽  
Nicola Armani ◽  
Carlo Zanotti-Fregonara ◽  
Enos Gombia ◽  
Martin Albrecht ◽  
...  

AbstractYellow luminescence (YL) has been studied in GaN:Mg doped with Mg concentrations ranging from 1019 to 1021 cm−3 by spectral CL (T=5K) and TEM and explained by suggesting that a different mechanism could be responsible for the YL in p-type GaN with respect to that acting in n-type GaN.Transitions at 2.2, 2.8, 3.27, 3.21, and 3.44 eV were found. In addition to the wurtzite phase, TEM showed a different amount of the cubic phase in the samples. Nano tubes with a density of 3×109 cm−2 were also observed by approaching the layer/substrate interface. Besides this, coherent inclusions were found with a diameter in the nm range and a volume fraction of about 1%.The 2.8 eV transition was correlated to a deep level at 600 meV below the conduction band (CB) due to MgGa-VN complexes. The 3.27 eV emission was ascribed to a shallow acceptor at about 170-190 meV above the valence band (VB) due to MgGa.The 2.2 eV yellow band, not present in low doped samples, increased by increasing the Mg concentration. It was ascribed to a transition between a deep donor level at 0.8-1.1 eV below the CB edge due to NGa and the shallow acceptor due to MgGa. This assumption was checked by studying the role of C in Mg compensation. CL spectra from a sample with high C content showed transitions between a C-related 200 meV shallow donor and a deep donor level at about 0.9- 1.1 eV below the CB due to a NGa-VN complex. In our hypothesis this should induce a decrease of the integrated intensity in both the 2.2 and 2.8 eV bands, as actually shown by CL investigations.


JETP Letters ◽  
2004 ◽  
Vol 79 (8) ◽  
pp. 365-367 ◽  
Author(s):  
A. V. Andrianov ◽  
A. O. Zakhar’in ◽  
I. N. Yassievich ◽  
N. N. Zinov’ev
Keyword(s):  

ACS Omega ◽  
2021 ◽  
Author(s):  
Jincheng Zeng ◽  
Gang Liu ◽  
Yu Han ◽  
Wenwei Luo ◽  
Musheng Wu ◽  
...  

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