materials providing invisibility to electronics
- 1. WELCOME TO THE WORLD OF INVISIBLE ELECTRONIC BY ANKIT KUMAR GIRI
- 2. WHAT IS THIS ??? Invisible electronic devices
- 3. INTRODUCTION • Transparent electronics also known as invisible electronics is and emerging technology. • It employs wide band gap semiconductor and opto-electronic devices. • It employs nano technology for the formation of circuits. • The backbone of these devices are Transparent conductive oxide(TCOs) and Thin film transistors(TFTs). • Some common TCOs are Indium oxide, zinc oxide and tin oxide. • TFTs is the bridge between the transparent and normal devices.
- 4. MATERIAL’S PROVIDING INVISIBILITY 1. Thin film transistor(TFTs) 2. Transparent conductive oxide
- 5. THIN-FILM TRANSISTOR • TFTs are made up by combining organic as well as inorganic transistor. • It is a bridge between the active and a passive electronic applications. • TFTs were first introduce in 1961 by Weimer via vacuum evaporation. • The mobility of TFT is more than that of passive(normal) transistor. • It is mostly made up of crystalline silicon and transparent electrodes.
- 6. MANUFACTUR E TFTs are commonly made of silicon . The layer of TFTs can be either amorphous silicon , microcrystalline silicon etc. Other material used in TFTs include compound semiconductor like cadmium selenide or transparent oxide like zinc oxide. Transparent electrode such as indium tin oxide is used to make the TFTs fully transparent. Chemical vapour deposition and physical vapour deposition are used to deposit zinc oxide.
- 8. TRANSPARENT CONDUCTING OXIDE(TCO) • TCOs are thin films optically transparent and electrically conductive materials. • They provide optical transparency to the electronic devices. • Indium tin oxide(ITO) commonly called as indium oxide is the most widely used TCO. • Other TCOs are fluorine doped tin oxide , doped zinc oxide etc. • These films are typically used as electrode when situation calls for it. • Use of TCOs are the traditional way to make a device transparent.
- 9. WORKING OF TCO • Transparent conducting oxide(TCOs) are doped metal oxides. • TCOs used in industries are primarily of n-type i.e it as donors electrons. • This is because the mobility of electron is higher than the holes. • The electron and holes are developed in tco because of following reasons -: 1. Interstitial defect and point defect. 2. Doping 3. Oxygen vacancies • 1st and 3rd sources always acts as a donor . They donate electrons.
- 11. NANOTECHNOLOGY IN ELECTRONICS • This term is commonly known as nano-electronics in electronics world. • Nano-technology is used to make devices like optoelectronics , displays etc. • Carbon nanotubes are used to built transparent electronics. • Nanowires enables flat panel display to be flexible. • Semiconductors nanowires are used to built IC and transistors.
- 12. CARBON NANOTUBES IN INVISIBLE ELECTRONICS•University of southern California(USC) has demonstrated the great potential of aligned carbon nanotubes in transparent electronics. •The are a tube like structure having dia. 50 to 60 nm. •Nanotubes are viable active materials for transparent transistor. •It provides the device with high performance with high
- 14. INVISIBILITY CLOAK • A cloak of invisibility is a method of making a physical objects undetectable or invisible. • The device works by producing mirage. • This technology is based on the properties exhibited by metamaterials. • Invisibility cloak just hide the things by bending the light. • This property of invisibility cloak is used in radar systems.
- 15. STRENGTHS AND WEAKNESSES STRENGTH • Visible transparency • Large area • Low cost(solution based deposition and printing) • Passive element (R&C)availability • Safe and non-toxic. WEAKNESSES • High resistance of tco. • Technical immaturity • Low frequency of operation.
- 16. CONCLUSION • Transparent electronics now holds the key for many future advancement. • It is leading us to new application. • Transparent devices are more efficient and attractive. Lets hope we are going to see this technology being implemented in our lives...!!!!