Moletronics or molecular electronics - technical seminar

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MoletronicsMolecular electronics- an invisible yet, revolutionary technologyPresented by Sukhwinder Singh

Directing StaffAsst Prof M Priyadharsini

TO GIVE AN INSIGHT ABOUT USE OF MOLECULAR TECHNOLOGY IN FIELD OF ELECTRONICSAIM

INTRODUCTIONBRIEF HISTORY MTRLS USED IN MOLETRONICSMOLECULAR ELEC COMPONENTSCHAR OF MOLECULAR DEVICESADV AND ROADBLOCKSAPPLNSFUTURE DEVELOPMENTSPURVIEW

First computer

Latest computer

INTRODUCTION

Moores law states that

The number of transistors per square inch on integrated circuits will double every year.

MOORES LAW

Different scales of Silicon Integration Technology

WHAT AFTER ULSI

IS IT THE END??????MOLETRONICS

It is branch of electronics in which individual molecules perform in same function as microelectronics devices such as diode or transistors.ORMoletronics is a subset of nanotechnology dealing with the manipulation of molecules so they work together as electronic circuits.

MOLETRONICS

BRIEF HISTORY

MTRLS USED IN MOLETRONICS

MTRLS USED IN MOLETRONICSORGANIC POLYMERSDiscovered in mid 1970s.Polymers are flexible, versatile and easy to process.Behave like a conventional inorganic semiconductor. Low mobility.Absence of band gap of the order of 0.75 to 2 e V.

Chemical formulae (C6H5) x Highly flexible Capable of carrying and switching currents.Very high current density(~.5 million times of Copper wires)Used as molecular wires and switches.

MTRLS USED IN MOLETRONICSPOLYPHENYLENE BASED CHAINS

MTRLS USED IN MOLETRONICSPOLYPHENYLENE BASED CHAINS

Alkyldithiol

Oligo(p-phenylene)-dithiol

(p-phenylene ethynylene)-dithiol.

Used as molecular wires or Bucky tube. High conductivity when used on micro patterned semiconductor surface ranging from excellent conduction to pretty good insulation..Differ in diameters and chiralityChemically stable but made only under extreme conditionsMTRLS USED IN MOLETRONICSCARBON NANOTUBES

MOLECULAR ELECTRONIC COMPONENTS

Nodes + Atomic nucleiCannot transport unimpeded electrical currentActs like resistorsAliphatic Molecular Insulators

Consists of 3 benzene ringsCentre ring has asymmetric fragmentsGreat flexibility and can even function when it is bent. MOLECULAR TRANSISTORS

Rectifying DiodesAlso called molecular rectifierAllows ct flow in only one dirnResonant tunneling Diodes(RTDs). Ct in both dirnsUses electron energy quantization Molecular Diodes

Nonlinear I-V Behavior Energy Dissipation Gain in Molecular Electronic CircuitsSpeed

CHARACTERISTICS OF MOLECULAR DEVICES

SizeSpeedAssemblyLow Manufacturing CostAble to integrate large circuitSynthetic flexibility/Re-configurable.StreochemistryGreater memory hold time

Advantages of Molecular Electronics

Advantages of Molecular Electronics

COMPARISION WITH BULK ELEC

Hard experimental verificationControlled fabrication within specified tolerancesMOLETRONICS ROADBLOCKS

Techniques for electrical characterization of molecules

(A) Hg drop junction. (B) Mechanically controlled break junctions. (C) Nanopore. (D) Nanowire. (E) Nanoparticle bridge. (F) Crossed wires. (G) STM. (H) Contact CP-AFM. (I) Nanoparticle coupled CP-AFM.Various techniques to measure electronic properties of molecules.

Molecular SensorsMolecular tweezersMolecular SwitchMolecular MotorsLogic and memory devicesSmart FabricsAPPLNS

FUTURE DEVELOPMENTS

MEMORY STORAGE APPLNSData storage is done by multiporphyrin nanostructures into electronic memory. The application of a voltage causes the molecules to oxidize, or give up electrons.The molecules then retain their positive charge after the electric field is removed, producing a memory effect.

MEMORY HOLD TIMESilicon memory devices = 1 mili sec Moletronic device = 15 minSo less power

CONCLUSIONThe Next Big Thing is very, very small. Picture trillions of transistors, processors so fast their speed is measured in terahertz, infinite capacity, zero cost. It's the dawn of a new technological revolution - and the death of silicon.

"Large-scale synthesis of carbon nanotubes", T W Ebbesen and P M Ajayan Nature, vol.358, p220 (1992 published)Scientific forum http://www.calmec.com/scientif.htmSearch http://www.calmec.com/search.htmwww.ieee.orgStrategic Technologies for the Military: Breaking New FrontiersBy Ajey Lelehttp://technews.acm.org/articles/2002-4/0805m.htmlhttp://www.wikipedia.comREFERENCES

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