1887 days ago, 705 views
PowerPoint PPT Presentation

Presentation Transcript

Slide 1

RUSSIAN-ARMENIAN STATE UNIVERSITY PHYSICO-TECHNICAL DEPARTMENT Ovsep Emin Str.123,Yerevan, Armenia Prof. Stepan Petrosyan email: Dr. Vladimir Gevorkyan email:

Slide 2

Growth and research of InAsSbP/InAs and Cu 2 O based heterostructures for photovoltaic and thermophotovoltaic applications Development of novel mechanical strategies for the development of III-V and ZnO nanowires for opto-and microelectronic gadget applications Theoretical and trial investigation of high productivity quantum speck sun based cells Theory of nanoscale contacts and nanodevices (photodiodes, field-impact transistors, position-touchy indicator) Field of Scientific Activities

Slide 3

Novel diode heterostructures on the base of InAs amalgams Fields of utilizations Medical Diagnostics: glucose and different substances in blood, in tissue Water Sensors: water in paper, water in grain, water in oil items. Methane Sensors: for methane spillage in houses, along gas interchanges, in mines Medical Diagnostics: Carbon Dioxide, Acetone and gasses in breath Mid IR Photodiodes Ecological checking of various modern poisons in air and water Systems of optical strands correspondence Free-space optical connection Energy generation and vitality sparing applications Thermophotovoltaic

Slide 4

ħ ω <E g ħ ω <E g Selective optical channel/reflector TPV cell ( E g ) Heated body ( emitter ) 1000-2000 О С Source of warm or sun based vitality Backside reflector Sources of sun powered and warm vitality for direct change to power on the base of TPV cells Engineering model of sun oriented vitality converter on the base of TPV cell Thermophotovoltaic converters

Slide 5

Relative ghastly reaction of the n + - InAs/n 0 - InAs/p + - InAs 0.27 Sb 0.23 P 0.5 TPV diode heterostructure developed by non-balance MOVPE development procedure S l, max = 1.4 - 1.6 A/W h = 0.4 - 0.5 Flexibility of the warmth source, which incorporates sun based and other warm wellsprings of vitality Compact in size Light weight Low Noise TPV converters can give 24 hours of power because of consolidating sun based vitality and warm vitality (burning fire, and so on)

Slide 6

Band graph of the n-InAs/p-InAs 1-x-y P x Sb y TPV diode heterostructure E C E g2 ħω E F E V E g1 n-InAs Substrate p-InAs 1-x-y P y Sb x emitter layer Sapphire Window Photo-diode Chip Amplifier Mid-Infrared photodiodes Epitaxial film prepared for Mid-IR gadget fabricating Pilot model of Mid-IR Photodetector with allegorical reflector and enhancer as a last item. Most extreme affectability without reflector ~1 nWatt. Bundled Mid-IR photograph diode. Schematic view and photograph of a building model of infrared photograph diode.

Slide 7

Quantum Dot Solar Cell: Structure Schematic chart of QDSC Corresponding vitality band structure

Slide 8

Experimental results Theoretical results Quantum Dot Solar Cell: Results Photocurrent thickness versus number of stacked layers contrasted and the photocurrent without QD's. Correlation of outer quantum proficiency of the sun powered cells with various stacked layers and without spots

Slide 9

2D p-n JUNCTION l ~ V QW thickness subordinate inherent potential Small capacitance with log reliance on voltage Very huge breakdown voltage High 2D electron versatility

Slide 10

V А =-4 eV  (x) V A = 0 V А =4 eV z + 2дэг - 2д Металл + - + - + - + - l x + - + - + - + 2D Shchottky contact

Slide 11

x V G 2 a + W ( y ) V S V ( y ) V D W ( y ) + y L V G 2D electron gas field efect transistor 2DEG High channel conductivity Very high transconductance .

Slide 12

Laser Synthesis of the Colloidal Nanoparticles Laser removal of materials in fluids Technique Applied: Semiconductor Nanoparticles (Quantum Dots) Metal Nanoparticles Carbon Nanoparticles Polymer Nanoparticles

Slide 13

Quantum Dots Blue - Ultraviolet Luminescence Ultrafine Sizes: 2-3nm

Slide 14

Ultrafine nano[particles in natural imaging In a frog fetus has been imaged utilizing natural color methods (b) Quantum Dots An imperative part of QD marks is their to a great degree high photostability, which permits observing of intra-cell forms over drawn out stretches of time The slim structure, is uncovered with fluorescence microscopy as nanocrystal quantum specks circle through the circulatory system.

Slide 15

Cancer Therapy&Diagnostics Specific marking of live cells with Quantum Dots Breast malignancy cells (An) and mouse mammary tumor tissue segment (B) were recolored with QDs

Slide 16

Magnetic Liquids M agnetic nanoparticles with molecule sizes sufficiently little to go through the fine frameworks of organs and tissues Their development in the blood can be controlled with an attractive field Nanostructures The capacity to build nanoassemblies guarantee for another era of hardware , and optoelectronics Carbon Micro/Nanofibers plasmonic subwavelength w aveguiding Plasmonic optoelectronics

Slide 17

6 1 4, 5 3 2 Actually, as it takes after from Fig. 1, NMR reaction precipitately changes upon the variety of the cover's substance. These information talk about the of the copper's valence state increment from 2 to 2+δ. Apparently, this is the hidden reason of Ts increment by 1 to 3 degrees. Fig.1. Cu2+(I) of the super leading Y 1 Ba 2 Cu 3 O 6.97 earthenware production (bend 1); and composites with HMPE. Bend 2 – 1% ; Curve 3 – 3% ; Curve 4 – 5% ; Curve 5 – 10 % ; Curve 6 – 20 % .

Slide 18

Superconducting polymer-fired nanocomposites are acquired with different folios (superhighmolecular polyethylene, SHMPE; ramified polyethyelene, RPE; copolymerfluorine with polyethyelene, F-40; polyvinylidene fluoride, PVIF, and so on.). From the information in table it takes after that the basic move temperature (T s ) is higher by 1–3 degrees versus the underlying fired (93 K). SC properties of polymer-earthenware nanocomposites in view of Y 1 Ba 2 Cu 3 O 6,97 fired ( Т pressing=140 о C,  pressing=30 min.). Intercalation of the macromolecules or their pieces into the fired grain's interstitial layer is affirmed by NMR apparatus technique (Fig. 1), and in addition by concentrating on the dynamical-mechanical properties (Fig. 2) and the morphology of the got nanocomposites (Fig. 3). Really, as it takes after from Fig. 1, NMR reaction precipitately changes upon the variety of the cover's substance. These information talk about the of the copper's valence state increment from 2 to 2+δ. Apparently, this is the basic reason of Ts increment by 1 to 3 degrees. 18

Slide 19

Temperature-to-mechanical-misfortunes'- scattering variable interrelation is influenced by the nearness of Y 1 Ba 2 Cu 3 O 6,97 fired. This is another affirmation of intercalation that remains constant. From Fig. 2 it takes after that both the low-temperature (T is ca –130 0 C; - 100 0 C) and high-temperature move (T is ca 130 0 C; 140 0 C) Fig2. Temperature reliance of tg  for the immaculate HMPE and for the HMPE fired composite. Clay content (weight %): bend 1-0%; 2 – 15%. 19

Slide 20

Intercalation of the macromolecules or their parts into the fired grain's interstitial layer, clearly, must affect the fastener's morphological structure. Without a doubt, as it could be found in Fig. 3, fibrillar structures are shaped in the artistic fastener interface. This is not at all like to polyolefin folios. Fig3. Microphotography of polymer-clay nano composites at various polymer to artistic proportion: Y 1 Ba 2 Cu 3 O 6,97 : HMPE =50:50 (a), 70:30 ( b ) 85:15 ( с ) 90:10(d). 20

Slide 21

One meanders in the event that it is conceivable to acquire polymer-earthenware nanocomposites with Meissner impact allowing high heap of streams to pass? Expansion of nanosized aluminum (30 nm) or silver (40 nm) into the polymer-fired composite produces nanocomposites with zero esteem resistance (Fig. 4). Fig4. Resistance change of the SC polymer artistic nano composite Y 1 Ba 2 Cu 3 O 6,97 with nano aluminum relied on upon HMPE content 21

Slide 22

Upon the change of fastener's substance one could get nanaocomposites with 1.6·10 3 A cm –2 current thickness loads. Deagglomeration and uniform spatial circulation of nanoparticles expands current thickness up to 3·10 3 A cm –2 . Fig.5. Reliance of the present thickness on the cover's substance. It is to be focused on that current-conveying polymer-artistic nanocomposites have rather great physical-mechanical properties. For instance, the accompanying qualities (extreme quality is 0.73 kg cm –2 ; modulus of versatility is 7.5 kg cm –2 ; lengthening is 2–3%) displayed a nanocomposite of the equation: Y 1 Ba 2 Cu 3 O 6,97  : binder : nano aluminium = 95 : 3.5 : 1.5. 22

Slide 23

Periodically surveyed lithium niobate gems another method for making of intermittently surveyed space structure in lithium niobate (PPLN) precious stones specifically amid the development procedure was created by the gathering of Dr.E.Kokanyan at the IPR NASA. The said strategy was effectively utilized for the development of immaculate and in addition doped with different transitional metal and uncommon earth pollution particles PPLN precious stones. The controlled arrangement of 4-50  m wide areas along the a-pivot of the precious stones in lengths of 20mm without intrusions or tweaks in space estimate and with more than 3mm of the space reversal profundity was conceivable. Checking race magnifying lens (SEM) micrograph of a scratched surface of as-developed hafnium doped lithium niobate precious stone. E.Kokanyan, V.Babajanyan, G.Demirkhanyan, J.Gruber, S.Erdei. J. of Appl. Phys., 92 , 1544 (2002). E.P.Kokanyan, L.Razzari, I.Cristiani, V.Degiorgio and J.B.Gruber. Appl . Phys. Lett . , 84 , 1880 (2004)

Slide 24

Wavelength converters in light of PPLN Another perspective is a solid confinement to the mechanical use of wavelength converters in view of PPLN precious stones, which originates from the so ca