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Curriculum Vitae
Cherukupalli Rajesh
Office:
Department of Physics
K. L. University,
Green Fields,
Vaddeswaram- 522 502. India.
Home: F. No.: 127, Indira Enclave, New
C. K. Reddy Road, New
Ayodhya Nagar, Vijayawada-
520003, India.
Mob.: +91 9441063672
Email : [email protected]
Date of Birth : May 12, 1981.
EDUCATION:
1. Ph. D. in Physics declared on 5th May 2012 from Department of Physics,
University of Pune, Pune, India.
Dissertation Title: “Optical Perspectives of Silicon and Doped ZnSe Quantum
Dots”. (Summary of work is enclosed).
Supervisors: Prof. Shailaja Mahamuni, and Prof. S.V. Ghaisas.
2. M. Sc. in Applied Physics with 69.9 % from Shri G. S. Institute of Science and
Technology, Indore, India. (August 2004)
Dissertation Title: “Second Harmonic Generation in Powdered samples – A New
Approach”.
CV: Cherukupalli Rajesh [email protected]
Page 2 of 16
Supervisor: Prof. Pratima Sen
3. B. Sc. in Electronic Equipment Maintenance with 73.6 % from P. B. Siddhartha
College of Arts and Science, Vijayawada, India. (May 2002)
Thesis Title: “Satellite Receiver”.
Supervisor: Prof. T. Venkateshwarlu.
4. H. S. C (12th) in Maths, Physics, and Chemistry with 73.3 % from Board of
Intermediate, Hyderabad, India. (May 1999)
5. S. S. C (10th) with 49.1 % from Council for the Indian School Certificate
Examinations, New Delhi, India. (March 1997)
RESEARCH INTEREST
(1) Synthesis of nano-materials.
(2) Optical properties of nano-materials.
(3) Structural properties.
(4) Photovoltaics.
(5) Low temperature measurements.
RESEARCH CONTRIBUTION:
During my Ph.D, the concept of coating Si QDs over a single crystal Si solar cell to
improve the conversion efficiency by virtue of surface passivation is demonstrated.
Coating a layer of Si QDs (hydrogen, oxygen, and 1-heptene passivated) on bare Si solar
cell leads to the improvement in short circuit current. The increase in efficiency of the
solar cell is a clear manifestation of reduction in surface recombination of charge carriers
resulting in improvement in the short circuit current.
CV: Cherukupalli Rajesh [email protected]
Page 3 of 16
The other part of work is to generate white light emission from the doped QDs is
explored. It is by virtue of high quantum efficiencies and low power consumption that the
QD based light sources of-late have assumed importance over the commercially available
semiconductor devices for white light generation. Property of doped QDs to give
impurity as well as band edge luminescence can be exploited to generate white light.
Copper (Cu) emission appears in green region, Manganese (Mn) emission in orange
region and that of ZnSe in blue region. Thus, if Mn and Cu are co-doped in ZnSe QDs
white light emission is possible. Experimental investigation shows the presence of Cu as
well as Mn in the same QD. Thus, these QDs can have a possible application in white
light emitting LEDs.
FELLOWSHIPS/RESEARCH EXPERIENCE:
(1) Junior Research Fellow on Indian Space Research Organization, India funded
research project: “Studies on Magnetic Semiconductors for Optical and/
Magnetic Sensors” from May 2005 to March 2007.
(2) Junior Research Fellow on Indian Space Research Organization, India funded
research project: “Exploring Semiconductor Quantum Dots for Solar Cell
Applications” from April 2007 to March 2008.
(3) Senior Research Fellow on Indian Space Research Organization, India funded
research project: “Exploring Semiconductor Quantum Dots for Solar Cell
Applications” from April 2008 to March 2009.
(4) Senior Research Fellow on Indian Space Research Organization, India funded
research project: “Study of Silicon Quantum Dots for Solar Cell Applications”
from May 2010 to May 2011.
CV: Cherukupalli Rajesh [email protected]
Page 4 of 16
PUBLICATIONS:
(Square bracket [ ] indicates the total number of citations obtained to the particular publication till date)
1) Magnetic Behavior of Manganese-Doped ZnSe Quantum Dots [32] (Impact
Factor: 2.101)
Amit D. Lad, Ch. Rajesh, Mahmud Khan, Naushad Ali, I. K. Gopalakrishnan,
S. K. Kulshreshthta, and Shailaja Mahamuni, J. Appl. Phys. 101, 103956 (2007).
http://jap.aip.org/resource/1/japiau/v101/i10/p103906_s1
2) Exciton recombination dynamics in zinc selenide quantum dots [11] (Impact
Factor: 1.458)
Ch. Rajesh, Amit D. Lad, Ajit Ghangrekar, and Shailaja Mahamuni, Solid State
Commun. 148, 435 (2008).
http://www.sciencedirect.com/science/article/pii/S0038109808005255
3) Two photon absorption in Mn2+-doped ZnSe quantum dots [16] (Impact
Factor: 1.480)
Deepak More, Ch. Rajesh, Amit D. Lad, G. Ravindra Kumar, and Shailaja
Mahamuni, Optics Commun. 283, 2150 (2010).
http://www.sciencedirect.com/science/article/pii/S0030401810000957
4) Absorption and luminescence of hydrogen and oxygen passivated silicon
quantum dots (Impact Factor: 0.49)
Ch. Rajesh, Shailaja Mahamuni, and S. V. Ghaisas, J. Nano-Electron. Phys. 3,
904 (2011).
http://jnep.sumdu.edu.ua/en/component/content/full_article/270
CV: Cherukupalli Rajesh [email protected]
Page 5 of 16
5) Water adsorption on oxygen passivated silicon nanoparticles [3] (Impact
Factor: 1.07)
Ch. Rajesh, Sumati Patil, S. Datar, D. Bhattacharya, A. K. Tripathi, Shailaja
Mahamuni, C. V. Dharmadhikari, and S. V. Ghaisas, Nanosci. Nanotech. Lett. 3,
622 (2011).
http://www.ingentaconnect.com/content/asp/nnl/2011/00000003/00000005/art000
04?token=00411c71046527afb23139412f415d7666344470557b597a407b382530
332948e
6) A Case Study: Te in ZnSe and Mn Doped ZnSe Quantum Dots [4] (Impact
Factor: 3.573)
Kiran G. Sonawane, Ch. Rajesh, Mayur Temgire, and Shailaja Mahamuni,
Nanotechnol. 22, 305702 (2011).
http://iopscience.iop.org/0957-4484/22/30/305702
7) Quantum confinement effect in pristine and oxygen covered silicon
nanocrystals with surface states (Impact Factor: 1.42)
Sudip Chakraborty, Ch. Rajesh, Shailaja Mahamuni, and S. V. Ghaisas, J.
Comput. Theor. Nanosci. 8, 1739 (2011).
http://openurl.ingenta.com/content?genre=article&issn=1546-
1955&volume=8&issue=9&spage=1739&epage=1743
8) Structural and optical properties of oxygenated silicon quantum dots [2]
(Impact Factor: 0.42)
Sudip Chakraborty, Ch. Rajesh, Shailaja Mahamuni, and S. V. Ghaisas, Adv. Sci.
Lett. 4, 3580 (2011).
CV: Cherukupalli Rajesh [email protected]
Page 6 of 16
http://www.ingentaconnect.com/content/asp/asl/2011/00000004/F0020011/art000
44?token=003f16550f0da35c5f3b3b47464c48783b44702e2b422a414f58762f67bf
2a7
9) Oxygen impact on quantum confinement effect for silicon clusters in
different size regimes: ab-initio investigations [1] (Impact Factor: 1.208)
Sudip Chakraborty, Ch. Rajesh, Shailaja Mahamuni, and S. V. Ghaisas, Euro. J.
Phys. D 64, 331 (2011).
http://epjd.edpsciences.org/index.php?option=com_article&access=standard&Ite
mid=129&url=/articles/epjd/abs/2011/11/d100456/d100456.html
10) Reduction in surface recombination through hydrogen and 1-heptene
passivated silicon nanocrystals on thin film Si solar cells* [6] (Impact Factor:
3.685)
Ch. Rajesh, M. R. Pramod, S. Patil, S. More, R. O. Dusane, Shailaja Mahamuni,
and S. V. Ghaisas, Sol. Energy 86, 489 (2012).
http://www.sciencedirect.com/science/article/pii/S0038092X11004130
*This paper is selected as one of the “Key Scientific Article” in Renewable
Energy Global Innovations.
http://reginnovations.com/key-scientific-articles/reduction-in-surface-
recombination-through-hydrogen-and-1-heptene-passivated-silicon-nanocrystals-
film-on-silicon-solar-cells/
11) First principles-based adsorption comparison of group IV elements (C, Si,
Ge, and Sn) on Au(111)/Ag(111) surface [1] (Impact Factor: 2.101)
Sudip Chakraborty, and Ch. Rajesh, J. Nanopart. Res. 14, 1187 (2012).
CV: Cherukupalli Rajesh [email protected]
Page 7 of 16
http://link.springer.com/article/10.1007/s11051-012-1187-8
12) Passivation of n-type emitter and p-type base in solar cells via oxygen
terminated silicon nanoparticles [3] (Impact Factor: 7.365)
Sumati Patil, Ch. Rajesh, M. R. Pramod, S. More, Shailaja Mahamuni, S. R.
Jadkar, R. O. Dusane, C. V. Dharmadhikari, and S. V. Ghaisas, Prog. Photovolt:
Res. Appl. 21, 1146 (2013)
http://onlinelibrary.wiley.com/doi/10.1002/pip.2318/abstract
13) Isoelectronic centers in quantum dots and photoluminescence decay
K. G. Sonawane, Ch. Rajesh, and Shailaja Mahamuni, “Advanced
Nanomaterials and Nanotechnology”, Springer Proceedings in Physics 143, 261
(2013).
http://link.springer.com/content/pdf/10.1007/978-3-642-34216-5_27#page-1
14) Electronic and optical properties of agglomerated hydrogen terminated
silicon nanoparticles: an ab-inito study (Impact Factor: 1.208)
Priya Francis, Sumati Patil, Ch. Rajesh, Sudip Chakraborty, Shailaja
Mahamuni, C. V. Dharmadhikari, and S. V. Ghaisas, Euro. J. Phys. D 67, 144
(2013).
http://dx.doi.org/10.1140/epjd/e2013-40052-3
15) Employing green synthesized silver nanoparticles as light harvesters in
nanostructured solar cells*[8] (Impact Factor: 0.961)
M. B. Rajendra Prasad, S. Deena, Ch. Rajesh, Vishal K. Pandit, and Habib M.
Pathan, J. Renew. Sustain. Energy 5, 031615 (2013).
http://dx.doi.org/10.1063/1.4807616
CV: Cherukupalli Rajesh [email protected]
Page 8 of 16
*This paper is selected in “World Energy News”.
www.cafe.gen.nz/node/56950
16) Generation of white light by codoped (Cu and Mn) ZnSe QDs [2] (Impact
Factor: 0.832)
Ch. Rajesh, Chinmay V. Phadnis, Kiran G. Sonawane, and Shailaja Mahamuni,
J. Exp. Nanosci. 10, 1082 (2015).
http://dx.doi.org/10.1080/17458080.2014.964340
17) Synthesis and optical properties of copper doped zinc selenide QDs [9]
(Impact Factor: 1.194)
Ch. Rajesh, Chinmay V. Phadnis, Kiran G. Sonawane, and Shailaja Mahamuni.
Physica Scripta 90, 015803 (2015).
CONFERENCES / SEMINARS:
1) Exciton Recombination Dynamics in Zinc Selenide Quantum Dots
Ch. Rajesh, Amit D. Lad, Ajit Ghangrekar, and Shailaja Mahamuni
Oral presentation in the 14th Raman Memorial Conference at Department of
Physics, University of Pune, Pune, India during February 22nd - 23rd, 2009.
2) Absorption and luminescence of hydrogen and oxygen passivated silicon
quantum dots
Ch. Rajesh, Shailaja Mahamuni, and S. V. Ghaisas
Poster presentation in International symposium on Semiconductor Materials and
Devices at M. S. University of Baroda, Vadodara, India during January 28th - 30th,
2011.
CV: Cherukupalli Rajesh [email protected]
Page 9 of 16
3) Study of silicon quantum dots for solar cell applications
Ch. Rajesh, Shailaja Mahamuni, and S. V. Ghaisas
Oral presentation in the 16th Raman Memorial Conference at Department of
Physics, University of Pune, Pune, India during February 25th - 26th, 2011.
4) Optical properties of copper doped ZnSe quantum dots
Ch. Rajesh, Chinmay V. Phadnis, and Shailaja Mahamuni
Poster presentation in 5th International Conference on Nanoscience and
Technology at Hyderabad, India during January 20th - 23rd, 2012.
5) Synthesis and optical properties of copper doped ZnSe quantum dots
Ch. Rajesh, Chinmay V. Phadnis, and Shailaja Mahamuni
Poster presentation in the 17th Raman Memorial Conference at Department of
Physics, University of Pune, Pune, India during March 2nd - 3rd, 2012.
6) Quantum confinement effect in prestine and oxygen covered silicon
nanocrystals with surface states
Sudip Chakraborty, S. V Ghaisas, Ch. Rajesh, and Shailaja Mahamuni
Oral presentation in DPG Spring Meeting, Regensburg, 21st - 26th March 2010 at
University of Regensburg.
http://www.dpg-
verhandlungen.de/year/2010/conference/regensburg/part/hl/session/49/contributio
n/1/?lang=en
7) Oxygen passivation effect on absorption spectra for silicon nanocrystals
Sudip Chakraborty, S. V. Ghaisas, Ch. Rajesh, and Shailaja Mahamuni
CV: Cherukupalli Rajesh [email protected]
Page 10 of 16
Poster presentation in Symposium J - Silicon-Based Nanophotonics of E-MRS,
June 7th-11th, 2010, Strasbourg.
http://www.emrs-
strasbourg.com/files/USB%2010/symposium_j.pdf?PHPSESSID=9ec6c2c6a4aff4
fbe089d6b906a60a36
8) White light generation from co-doped ZnSe quantum dots
Ch. Rajesh, Chinmay V. Phadnis, and Shailaja Mahamuni
Poster presentation in International Conference on Nanoscience + Technology
July 23rd – 27th, 2012, Paris.
AWARDS
R. Chandrashekhar Memorial Foundation’s, Late Dr. M. R. Bhide prize for the
paper having potential for industrialization in Raman Memorial Conference,
Pune (25th – 26th February 2011).
ACHIEVEMENTS
1. Reviewer of International Journals
a. Journal of Experimental Nanoscience (Taylor and Francis).
b. Materials Research Express (Institute of Physics).
c. International Journal of Nanoparticles (Inderscience Publishers).
d. Journal of Nano Research (Trans Tech Publications).
e. Applied Nanoscience (Springer).
f. Journal of Material Physics and Chemistry (Science Publications).
g. American Journal of Electrical and Electronic Engineering (Science
Publications).
CV: Cherukupalli Rajesh [email protected]
Page 11 of 16
h. Nanotechnology (Institute of Physics)
2. Editorial Board
a. Journal of Physical and Natural Sciences (International Scientific
Journal).
b. Journal of Material Research Science (Canadian Center of Science
and Education).
3. As a Course coordinator of M. Tech Nanoscience and technology, I achieved
overall 100 % result in the first semester.
4. Achieved 100 % results in both subjects which I taught in first semester
“Advanced Materials Technology (Course Code: NT-7103)” and
“Synthesis of Nanomaterials (Course Code: NT-7104)”.
TEACHING EXPERIENCE
[1] Worked as a “Guest Lecturer” on hourly basis at National Defence
Academy (NDA), Khadakwasla, Pune. (From July 2011 to December
2011).
[2] Worked as a “Guest Lecturer” on hourly basis at National Defence
Academy (NDA), Khadakwasla, Pune. (From February 2012 to June
2012).
[3] Worked as an “Assistant Professor” on contractual basis at National
Defence Academy (NDA), Khadakwasla, Pune. (From July 2012 to
May 2013).
[4] Worked as an “Assistant Professor” at G. K. M. College of Engineering
and Technology (G. K. M. C. E. T), New Perungalathur, Chennai.
(From 03 June 2013 to 29 November 2013).
[5] Working as an “Assistant Professor” at K. L. University, Vaddeswaram,
Guntur. (From 01 Jan 2014 to till date).
CV: Cherukupalli Rajesh [email protected]
Page 12 of 16
[6] Working as an “Assistant Professor/Head, Department of Physics” at
K. L. University, Vaddeswaram, Guntur. (From 07 Jul 2015 to till 13-
Dec 2016).
CV: Cherukupalli Rajesh [email protected]
Page 13 of 16
Summary of the thesis work:
“Optical Perspective of Silicon and Doped ZnSe Quantum Dots”
Silicon (Si) quantum dots (QDs) with various passivating molecules like
hydrogen, oxygen, and 1-heptene were synthesized by electrochemical as well as by wet
chemical method. The optical properties were studied with the help of optical absorption
(to determine band gap), luminescence (to detect whether it is a band-edge or surface
state related luminescence) and Fourier transform infrared spectroscopy (to know what
type of bonding). We have also studied the solar current versus voltage (I-V)
characteristics of these QDs by coating it over the single crystal silicon solar cell. The
efficiency of oxygen passivated Si QDs showed a maximum increase in the efficiency of
around 12 % and in all other cases the efficiency is around 6-9 %. There is an increase in
short circuit current only. The experimental data clearly indicates that the QDs must be in
contact with the solar cell. On the other hand, if film of QDs are separated from solar cell
by glass, short circuit current, in fact drops down. Moreover substantial enhancement in
reflectance is observed due to formation of Si QD layer on solar cell. Thus possibility of
nanocrystalline Si films acting as antireflection coating or scintillating layer is clearly
ruled out. The increased efficiency of the solar cells is a clear manifestation of reduction
in surface recombination of charge carriers resulting in improvement in the short circuit
current.
We have also observed water adsorption on Si QDs passivated with oxygen. A
temperature dependent reflectivity on Si surface is observed within a range of 30 to 100
0C. This is due to the water adsorption of Si QDs which tends to form agglomerates and
CV: Cherukupalli Rajesh [email protected]
Page 14 of 16
appears as nanopores. The optical inspection shows repeatable adsorption-desorption of
water with temperature. The temperature dependent FTIR and STM measurements show
that the interaction between water molecules and QDs surface. This is attributed to Si-O-
Si like bonds on the surface.
The other part of my thesis work involved synthesis of undoped ZnSe QDs of
different sizes and study its decay dynamics. With the help of time dependent
photoluminescence (TDPL) measurements, various radiative and nonradiative
recombination centers could be elucidated. TDPL measurements of three different sized
ZnSe QDs were performed. The existence of biexponential decay is explained with the
help of three level model [ground state, singlet (bright exciton) state, and triplet (dark
exciton) state]. The exciton recombination time of ZnSe QD decreases with the reduction
in quantum dot size.
Further, doping a transition metal into the host lattice is studied. By using high
temperature wet chemical route, we have doped two different transition metals viz.
manganese (Mn) and copper (Cu). Cu doping in ZnSe (Cu:ZnSe) QDs reveal remarkable
photoluminescence (PL) with the ability to tune the emission properties from blue to
green region, simply by increasing the size of the QDs. With this method Cu doping is
easy in comparison with other reports which took hours to get Cu incorporated into the
host lattice. By this method we can synthesize four different sized (from 2.0 ± 0.2 to 3.7
± 0.4 nm) doped ZnSe QDs. Synthesis of doped ZnSe QDs yielded high quality narrow
size distributed QDs. The optical absorption revealed quantum size effect. The
luminescence showed both band-edge and impurity related emission. Substitutional
doping is confirmed from photoluminescence excitation (PLE) measurements.
CV: Cherukupalli Rajesh [email protected]
Page 15 of 16
White light generation is achieved by simply co-doping the Cu and Mn ions into
the host ZnSe lattice. This synthesis method also offers us the feasibility to dope both Cu
and Mn in the same QD. Optical probes were used to study the presence of Cu as well as
Mn in these QDs. Emission spectra revealed three peaks related to blue (ZnSe), green
(copper related) and orange (manganese related). PLE measurements were carried out in
order to probe co-doping of Cu and Mn in the same QD. PLE spectra recorded with
emission wavelength fixed at Cu and Mn level showed band edge at the same position.
This indicates that both Cu and Mn are incorporated in the same QD. Since these QDs
emit almost in the entire visible range it can be used as white light emitting QDs by
improving the efficiency further.
CV: Cherukupalli Rajesh [email protected]
Page 16 of 16
REFERENCES:
(1) Prof. Shailaja Mahamuni,
Department of Physics,
University of Pune,
Ganeshkhind.
Pune – 411 007. India.
Tel: +91 20 25601410; Ext. 322.
Email: [email protected]
(2) Prof. S. V. Ghaisas,
Department of Electronic Science,
University of Pune,
Ganeshkhind.
Pune – 411 007. India.
Tel: +91 20 25699841.
Email: [email protected]
(3) Prof. Pratima Sen,
School of Physics,
Devi Ahilya University,
Indore - 452 017. India.
Tel: +91 731 2762153.
Email: [email protected]
