THIN FILM TECHNOLOGY : NAME-SANDIPAN KR.DAS(BANTI)
COLL ROLL-O6/CH/52 THIN FILM TECHNOLOGY Thin film technologies : The various thin-film technologies currently being developed reduce the amount (or mass) of light absorbing material required in creating a solar cell. This can lead to reduced processing costs from that of bulk materials (in the case of silicon thin films) but also tends to reduce energy conversion efficiency, although many multi-layer thin films have efficiencies above those of bulk silicon wafers. (Wikipedia, 2007c)
Thin-film cells offer advantages beyond cost, including pliability, and potential integration with preexisting buildings and infrastructure. (Crabtree & Lewis, 2007) Thin film technologies Slide 3: Novel conducting polymers enable solar cells that are flexible, inexpensive, and versatile. The new materials can be coated or printed onto flexible or rigid surfaces. (Image courtesy of Konarka Technologies.) (Crabtree & Lewis, 2007)
Thin Film Technology Corporation (TFT) is a passive electronic component manufacturer servicing; telecommunication, medical, computing, automotive, and signal integrity markets. Slide 4: TFT simulates, designs, and manufactures device and signal integrity solutions from its' ISO registered facility making shipments worldwide. Thin Film Technology utilizes thin film processes to build passive components used in data-communication, medical, computer, test equipment, power supplies, and automotive markets. TFT's wide variety of products include; termination networks, precision resistors, low pass & high pass filters, inductors, capacitors and delay lines. TFT's products are utilized in applications ranging from signal conditioning, compensation networks, equalization & de-emphasis, timing & deskew, to a myriad of other applications. Thin Film Advantages : Thin Film Advantages Simple fabrication
Requires low fabrication temp (300 C)
Manufacturing requires little materials. -thin cell to crystinal thickness= 1 to 300
High voltage can be obtained
No infrastructure needed to support cells
Cell can double as building material (roofing tiles, walls, etc) Types of Thin Film Technology : Types of Thin Film Technology There are primarily three types of thin film technologies that have each been researched for over 15 years and are the current focus of the solar industry:
1.Amorphous Silicon (a-Si)
2.Cadmium Telluride (CdTe)
3.Copper Indium Gallium Selenide (CIGS) Slide 7: Amorphous Silicon had the largest share of the thin film market (64%) as of the end of 2005. It has been researched for the longest period of time, may be the best understood material of the three and has been commercial for the longest. Cadmium Telluride had 26% share of the market and is ramping up very rapidly, with Copper Indium Gallium Selenide having a 10% share of the thin film market, with theoretically the greatest potential, but the least understood and least commercially developed of the three materials. Amorphous The efficiency of amorphous solar panels is not as high as those made from individual solar cells, although this has improved over recent years to the point where they can be seen as a practical alternative to panels made with crystalline cells. Slide 8: Their great advantage lies in their relatively low cost per Watt of power generated. This can be offset, however, by their lower power density; more panels are needed for the same power output and therefore more space is taken up. In general terms crystalline silicon modules provide higher power to area solutions than thin film amorphous technologies, however thin film technology is more cost effective. Figure 1 illustrates the main types of solar cells available on the market. Solar cells are usually made from silicon, the same material used for tranistors and integrated circuits. The silicon is treated or “doped” so that when light strikes it electrons are released, so generating an electric current. Slide 9: Different types of solar technologies Slide 10: Multi-crystalline or poly-crystalline cell: Poly or multi crystalline cells are made from wafers of silicon cut from a multi-crystal square cast ingot of silicon. Poly cells are smaller than mono cells, slightly less efficient, however have a cost advantage over mono-crystalline cells. These types of cells are the most commonly available modules used domestically worldwide. The cells are recognised by a blue flaked appearance of the cell, which is typically under glass.
In crystalline solar technology, the roughly 0.3 mm thick wafers made of the semiconductor material silicon are further processed to ensure that sunlight hitting them can be converted directly into solar power Slide 11: Mono-crystalline or mono cell: The name refers to the cell construction being from single (mono) crystal silicon. Mono crystalline cells are formed by cutting wafers of silicon from a large circular single crystal ingot of silicon. These wafers are then processed and used in round, half-round or trimmed square cells which are positioned under glass. The glass is usually framed in aluminium to allow easy mounting. Mainly made from a single large crystal, cut from ingots. Most efficient, but also the most expensive. Somewhat better in low light conditions. Slide 12: The table below provides a summary of the main differences between crystalline and amorphous technologies: Slide 13: Triple Junction Thin Film Cell: (United Solar Systems Corp., 2004) Slide 14: THIN FILM DEPOSITION TECHNOLOGY EVAPORATION [ HV, UHV, INERT GAS REACTIVE]
SPUTTERING [ HV, UHV, INERT GAS, REACTIVE]
PULSED LASER DEPOSITION[HV, UHV, INERT GAS, REACTIVE ] THERMAL GROWTH [PLASMA ASSISTED ]
[PLASMA ASSISTED ] CHEMICAL VAPOR DEPOSITION : CHEMICAL VAPOR DEPOSITION CONSERVATION OF CHEMICAL COMPOSITION : CONSERVATION OF CHEMICAL COMPOSITION Slide 17: SOME ELEMENTS OF THIN FILM GROWTH Growth Modes Slide 18: Future of Thin Films Natures solution to thin film cells.
developing molecules out of organic compounds ﾐ like carbon and hydrogen .
super-thin film about 100 nanometers thick, can be applied as a paint.
Replaces heavy metals currently being used in cells.
Creates a biodegradable, almost natural cell.