The study of HgCdTe MBE-grown structure with ion milling

2010 ◽  
Vol 18 (3) ◽  
Author(s):  
M.M. Pociask
Keyword(s):  
Molecular Beam ◽  
Ion Milling ◽  
Type Conversion ◽  
Defect Complexes ◽  
Conductivity Type ◽  
Equilibrium Processes ◽  
Before And After ◽  
P Type ◽  
Grown Structure

AbstractOf many techniques used to characterize quality of HgCdTe, ion milling is emerging as a unique means to reveal electrically active and neutral defects and complexes. Ion milling is capable of strongly affecting electrical properties of HgCdTe, up to conductivity type conversion in p-type material. It appears, that strongly non-equilibrium processes which take place under ion milling, when material is oversaturated with mercury interstitial atoms generated near a surface, lead to formation of specific defect complexes, which may not form under other type of treatment. By measuring parameters of a crystal before and after milling, and following disintegration of defects with time after ion milling (’relaxation’), one can detect and identify these defects. This method was applied to analyse different samples grown by molecular beam epitaxy.

Ion milling-induced conductivity-type conversion in p-type HgCdTe MBE-grown films with graded-gap surface layers

2010 ◽  
Vol 25 (6) ◽  
pp. 065012 ◽  
Author(s):  
M Pociask ◽  
I I Izhnin ◽  
S A Dvoretsky ◽  
Yu G Sidorov ◽  
V S Varavin ◽  
...  
Keyword(s):  
Ion Milling ◽  
Type Conversion ◽  
Surface Layers ◽  
Conductivity Type ◽  
P Type

Defect Complexes and Non-Equilibrium Processes Underlying the P-Type Doping of GaN

1998 ◽  
Vol 537 ◽  
Author(s):  
Fernando A. Reboredo ◽  
Sokrates T. Pantelides
Keyword(s):  
High Temperature ◽  
Experimental Evidence ◽  
First Principles ◽  
Final Anneal ◽  
First Principles Calculations ◽  
Defect Complexes ◽  
Equilibrium Processes ◽  
Open Questions ◽  
High Temperature Anneal ◽  
P Type

AbstractIt is well known that hydrogen plays a key role in p-type doping of GaN. It is believed that H passivates substitutional Mg during growth by forming a Mgs-N-Hi complex; in subsequent annealing, H is removed, resulting in p-type doping. Several open questions have remained, however, such as experimental evidence for other complexes involving Mg and H and difficulties in accounting for the relatively high-temperature anneal needed to remove H. We present first principles calculations in terms of which we show that the doping process is in fact significantly more complex. In particular, interstitial Mg plays a major role in limiting p-type doping. Overall, several substitutional/interstitial complexes form and can bind H, with vibrational frequencies that account for hitherto unidentified observed lines. We predict that these defects, which limit doping efficiency, can be eliminated by annealing in an atmosphere of H and N prior to the final anneal that removes H.

Conductivity type conversion of p-type CuInSe2 due to hydrogenation

2001 ◽  
Vol 179 (1-4) ◽  
pp. 203-208 ◽  
Author(s):  
K Otte ◽  
G Lippold ◽  
D Hirsch ◽  
R.K Gebhardt ◽  
T Chassé
Keyword(s):  
Type Conversion ◽  
Conductivity Type ◽  
P Type

Electrical Characterization and Defect-Related Luminescence in Oxygen Implanted Silicon

2015 ◽  
Vol 242 ◽  
pp. 368-373 ◽  
Author(s):  
D.V. Danilov ◽  
O.F. Vyvenko ◽  
N.A. Sobolev ◽  
V.I. Vdovin ◽  
A.S. Loshachenko ◽  
...  
Keyword(s):  
Positive Charge ◽  
Electrical Characterization ◽  
Luminescence Spectra ◽  
Type Conversion ◽  
Free Electron Concentration ◽  
Light Emitting ◽  
Conductivity Type ◽  
Significant Difference ◽  
P Type ◽  
Oxygen Precipitates

Defect structure, electrical properties and defect-related luminescence (DRL) of light emitting diodes (LED) with the active defect-rich region produced by oxygen implantation and a subsequent multistep annealing of silicon wafers were investigated. It was found that defect-rich regions possess an embedded positive charge in both n-and p-type of the samples whose origin was ascribed to oxygen precipitates (OP). The presence of that charge in the implanted region of p-based LED gave rise to the apparent conductivity type conversion and to a significant increase of free electron concentration in n-based LEDs. A significant difference in the shape and in the excitation dependence of luminescence spectra as well as in the properties of DLTS signals was found between p-and n-type samples. From an analysis of the obtained data the DRL band centered at 0.79 eV was ascribed to small OPs segregated at dislocations whose filling with the holes hinders optical transitions via dislocation-related states at 0.805 eV and the broad DRL band at energies higher than 0.81 eV was ascribed to large OPs.

High Resolution Photoluminescence of EDGE and Near-Edge CdTe

1992 ◽  
Vol 242 ◽  
Author(s):  
M. C. Carmo ◽  
M. J. Soares
Keyword(s):  
Heat Treatment ◽  
High Resolution ◽  
Crystal Quality ◽  
Luminescence Properties ◽  
Type Conversion ◽  
Edge Luminescence ◽  
Conductivity Type ◽  
The One ◽  
P Type

ABSTRACTAmong II-VI semiconductors CdTe is the one that can be grown in better crystal quality. However most of the edge and near edge luminescence properties are still to be clarified. CdTe can be obtained in both n and p type and conductivity type conversion is obtained under heat treatment.In this work we studied the behaviour of a batch of CdTe samples under annealing in different conditions. We observed the growth and destruction of the 1.47 eV band and separated the 1.47 eV and 1.43 eV bands. We also show that these bands are strongly related with the chemical stoi chiometry.

Conductivity type conversion in ion-milled p-HgCdTe:As heterostructures grown by molecular beam epitaxy

2007 ◽  
Vol 91 (13) ◽  
pp. 132106 ◽  
Author(s):  
I. I. Izhnin ◽  
S. A. Dvoretsky ◽  
N. N. Mikhailov ◽  
Yu. G. Sidorov ◽  
V. S. Varavin ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Type Conversion ◽  
Conductivity Type

Characterization of GaN p-n Junction Grown on Si (111) Substrate by Plasma-Assisted Molecular Beam Epitaxy

2011 ◽  
Vol 364 ◽  
pp. 139-143
Author(s):  
Radzali Rosfariza ◽  
Anas Ahmad Mohd ◽  
Hassan Zainuriah ◽  
Norzaini Zainal ◽  
Fong Kwong Yam ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Band Edge Emission ◽  
X Ray Diffraction ◽  
Sem Image ◽  
Raman Measurement ◽  
P Type ◽  
Sharp Interfaces

In this report, the growth of GaN p-n junction on Si (111) substrate by plasma-assisted molecular beam epitaxy (PAMBE) is demonstrated. Doping of the GaN p-n junction has been carried out using Si and Mg as n-type and p-type dopants, respectively. Silicon substrate is used to grow the GaNpn-junction. In order to improve the crystalline quality of the nitride based junction, AlN is used as a buffer layer. The optical properties of the sample have been characterized by photoluminescence (PL) and Raman spectroscopy.PL spectrum shows a strong band edge emission of GaN at ~364nm, indicating good quality of the sample.The presence of peak ~657cm-1in Raman measurement has exhibited asuccessful doping of Mg in the sample. The structural properties are measured by high-resolution x-ray diffraction (HR-XRD) and scanning electron microscopy (SEM). The cross section of the SEM image of the sample has shown sharp interfaces.

scholarly journals Defect Complexes and Non-Equilibrium Processes Underlying the P-Type Doping of GaN

1999 ◽  
Vol 4 (S1) ◽  
pp. 508-513
Author(s):  
Fernando A. Reboredo ◽  
Sokrates T. Pantelides
Keyword(s):  
High Temperature ◽  
Experimental Evidence ◽  
First Principles ◽  
Final Anneal ◽  
First Principles Calculations ◽  
Defect Complexes ◽  
Equilibrium Processes ◽  
Open Questions ◽  
High Temperature Anneal ◽  
P Type

It is well known that hydrogen plays a key role in p-type doping of GaN. It is believed that H passivates substitutional Mg during growth by forming a Mgs-N-Hi complex; in subsequent annealing, H is removed, resulting in p-type doping. Several open questions have remained, however, such as experimental evidence for other complexes involving Mg and H and difficulties in accounting for the relatively high-temperature anneal needed to remove H. We present first principles calculations in terms of which we show that the doping process is in fact significantly more complex. In particular, interstitial Mg plays a major role in limiting p-type doping. Overall, several substitutional/interstitial complexes form and can bind H, with vibrational frequencies that account for hitherto unidentified observed lines. We predict that these defects, which limit doping efficiency, can be eliminated by annealing in an atmosphere of H and N prior to the final anneal that removes H.

Non-metastable recombination induced reactions involving hydrogen in SiC

2004 ◽  
Vol 813 ◽  
Author(s):  
Yaroslav Koshka ◽  
Bharat Krishnan ◽  
Michael S. Mazzola
Keyword(s):  
Energy Gap ◽  
Hole Concentration ◽  
Optical Excitation ◽  
Electrical Measurements ◽  
Free Hole ◽  
Defect Complexes ◽  
Conductivity Type ◽  
Defect Reactions ◽  
Range Migration ◽  
P Type

ABSTRACTA brief survey of some of the recent results of recombination-induced defect reactions involving hydrogen in 4H and 6H-SiC is given. A variety of outcomes of such reactions have been observed in hydrogenated 4H and 6H-SiC polytypes under optical excitation at reduced temperature. A few different non-metastable hydrogen-defect complexes can form, including hydrogen complexes with Al and B acceptors, hydrogen complex with Si vacancy, as well as some other non-identified complexes. Electrical measurements indicated strong recombination-induced passivation of the electrical activity of aluminum and boron acceptors in SiC. This passivation resulted in the reduction of the net free hole concentration and even inversion of the conductivity type. It is suggested that optical excitation causes a long-range migration of hydrogen followed by its capture in one or another kind of defect complexes. Further insight in the formation of specific complexes as a result of recombination-induced defect reactions is provided by thermal admittance spectroscopy. Energy gap levels in the regions that remained p-type after hydrogenation as well as in the regions where the conductivity was inverted by the recombination-induced passivation are investigated.

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